Page 1 Written directions and instructional videos:

Figure 1: T-thermometers {(T1, T2, T3, T4, T5, T6, from left to right; (top figure) and (T7, T8, T9,) from left to right; (bottom figure)}

Description:

Vertical T-thermometers are composed of a left outside red line and a right outside blue line, with black horizontal lines (called hash marks) separating the thermometer into 10 segments, with the narrowest segment at the bottom of the thermometer and the widest segment at the top. A horizontal thermometer is identical, and is created by either rotating your phone to the left or right-hand side, as you align your phone with your either your astigmatism or spherical axis; but never in an upside, down, position, that is, on all readings the bottom of the phone must be equal to, or below the top of the phone. {These terms (and all new, terms) will be described in detail below.}

 

T1, T2, T3, T4, T5, T6

 

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T7,    T8,    T9

 

 

 

 

 

 

 

 

 

 

 

 

 

Since a picture is worth a thousand words, we are starting with the videos, to hopefully  save you from having to read the written instructions)

Videos demonstrating the 5 types, of possible refractive errors:

(Always ok to magnify the videos if needed)

If you know that you are nearsighted (distance vision is much blurrier than your near vision), then watch the videos for the 2a, 2b, and 2c types of refractive error below. This will allow you to define the specific type of refractive error that each of your eyes have, and how to measure your refractive error.
If you know that you are farsighted (near vision is blurrier than your distance vision), then watch the 2d and 2e videos below.
If you are not sure which one you are, then view the T-thermometers, (T1-T9), on your I-phone from your standard reading distance (while overlooking the phone placed on a on a chair in front of you).  First download the narrative on the actual word document at the bottom of this page (URL address at the bottom of page 1). Next, while testing each eye, one at a time, while closing your other eye; find the widest segment on the T-thermometers, that first shows a well defined vertical white space (CWS), separating the two blurs from each other within that segment. If this vertical thin white space is located just inside the nasal line (darkest line closest to your nose, red line for right eye readings, blue line for left eye readings) then you are probably farsighted. If the vertical white space is located just inside the temporal line (darkest line closest to your temple, blue line for right eye readings, red line for left eye readings) then you are probably nearsighted.
If no white space separates the blurs then use the wider T-thermometers, (T10-T21), at the bottom of the narrative.

Nearsighted refractive error (2a):

      • Videos showing an initial T-thermometer reading, and then an inflexion point target reading, for a (2a) eye, demonstrating how to define 2a as your refractive error.
      • (hyperlink 2aTt— https://youtu.be/SoxF2W2IYUo

2aIPt— https://youtu.be/TWaQ5ZtjEX4 ).

Nearsighted astigmatism refractive error (2b)

      • Video using an initial T-thermometer reading, showing how to define your eye as having 2b refractive error, (where the lines along both of your visual axes, can be brought into perfect focus, first after your phone has been aligned along one of your visual axes, and then later when rotated 90 degrees to be aligned along your other visual axis), and how to determine your astigmatism axis in degrees, using  the astigmatism target (figure 2). {error in the video- (149 degrees instead of 159)} (hyperlink (2bTt)— https://youtu.be/7_9p3_5Z9YU

{or by using an inflexion point target (IPt)}

Part 1, hyperlink 2bIPt—             https://youtu.be/7PzFFMHD1b4

Part 2, hyperlink 2bIPt—

https://youtu.be/z8XaorfP0u4

Mixed astigmatism (2c)

3.Video showing an initial T thermometer reading for a (2c) eye, (where only one line can be brought into perfect focus, (with sharp defined edges), by aligning your phone along your spherical axis), demonstrating how to define 2c as your refractive error, and how to determine your astigmatism axis in degrees using the astigmatism target (figure 2). (hyperlink 2cTt)—   https://youtu.be/28SooHFCYfY

(or by using an inflexion point target)—

(hyperlink 2cIPt)   https://youtu.be/YlxA7exId8U

Videos showing how to distinguish 2a, 2b, and 2c, from each other using just an astigmatism target.

2a—      https://youtu.be/fZQfmJohqdk

2b (part 1)         https://youtu.be/5A-5wH8uUR8

(part 2)        https://youtu.be/6xsdD0Qs1Co

2c—         https://youtu.be/Qnt0AwUSd-

Farsighted refractive error (2d)

      • Video showing an initial T thermometer reading, and an initial inflexion point target reading for a (2d) eye, demonstrating how to define 2d as your refractive error (hyperlink)

2dTt—      https://youtu.be/AEZxVZb6N5I

2dIPt (SRD)—     https://youtu.be/DGFPlAJF8gw

Farsighted astigmatism refractive error (2e)

      • Video using an initial T thermometer reading, and an inflexion point target reading; showing how to define your eye as having 2e refractive error, and determine your astigmatism axis in degrees. (hyperlink

2eTt—      https://youtu.be/gV4OmBFuoBI

2eIPt—    https://youtu.be/h8P_p1ceU_E

Often from just reviewing the videos, above, and by testing one eye at a time with the other eye closed or covered, you will be able to recognize the type of refractive error you have, and, successfully complete your initial answer sheet. During this same reading, you can also measure your neutral points, as indicated, if you are nearsighted overall (2a), or nearsighted along one or both of your visual axes (2c, or 2b). If this is the case, and you have either 2a or 2b refractive errors, it is not necessary to read the written instructions below, you have already completed your reading. However, if this is your first reading, it may be  best, to at least review the brief written instructions below, or even the detailed written instructions, if you still have questions. If you have 2c, 2d, or 2e refractive errors  move onto Section2 for instructions on how to obtain a farsighted reading along one or both of your visual axes, to complete your final readings. 

Written Directions:

Brief instructions:

Nearsighted reading (distance vision is blurry, vision is good up near):

For a nearsighted measurement, for an eye without astigmatism, your end point for making a measurement is made with a tape measure, from the bony corner of your eye, to the phone’s screen, with the phone placed vertically in a chair in front of you, while directly overlooking the phone, and focusing on the visual target {T1-T6 at the top of this narrative}, (with your other eye closed or covered). After initially beginning at a distance from the phone where the red line on T1 widest segment appears blurry; and then slowly and incrementally approach the phone, (double blinking in between each movement forward), until the red line first becomes in focus (that is, its outside edges first appear to be sharp and in focus). Next confirm that the line also appears at its widest, by making a slight movement forward and notice that the red line narrows or blurs slightly, and the same thing happens if you move slightly outward from the phone. This establishes that you have found your neutral point or distance from the phone where your nearsighted refractive error has been completely neutralized or eliminated. Confirm your neutral point by a double blink, and by noting that the red line is remaining in focus over the next 5 seconds or so, as your eye being tested remains relaxed, as opposed to the line narrowing or blurring over that 5 secs while your eye works to keep the image in focus for you. If the latter is the case, it usually means you are closer than your actual neutral point. Just start over and re-measure. By measuring your neutral point to the nearest 1/32″, or nearest mm, we can determine your refractive error for that eye.

If your eye has astigmatism in addition to being nearsighted, which can be determined just by rotating your phone in either direction,  and noticing that the image (red line) appears in better focus when rotating the phone in one directions and gets blurrier when rotating the phone in the opposite direction. If this is the case, rotate the phone in the direction where the red line was getting clearer, until you have adjusted both the phone’s rotation, and your head’s distance from the phone to get the line into perfect focus. Test your new neutral point by rotating the phone slightly off your visual axis, in both directions, and noting that the red line either widens, fades, or blurs slightly, and then retest your distance from the phone’s screen, by moving your head, slightly nearer, or away from the phone’s screen, and again noticing the red line narrows or blurs slightly, confirming, now that all the astigmatism refractive error has been neutralized or eliminated, as well as all the nearsighted refractive error, allowing you to determine your neutral point along that visual axis, by again measuring with a tape measure from the bony corner of your eye to the phone’s screen.

Next, rotate the phone 90 degrees, (by placing a ruler directly horizontal to you on the face of the phone, and then rotating the phone upward, so that now the ruler is exactly vertical to you), and measure your new neutral point by now adjusting only your distance from the phone where the red line again, becomes in perfect focus, and appears to be at its widest, at this new distance from the phone. If this new distance or neutral point is closer to the phone (has a smaller measured value), this confirms your original visual axis was your astigmatism axis, and your new axis is your spherical axis. If you had to move further from the screen to get the red line in focus, then this confirms your new visual axis is your astigmatism axis, and your original visual axis was your spherical axis. After measuring your neutral point along this visual axis as well, record your values on your initial answer sheet, or write down your answers, for your specific visual axes, (either spherical visual axis, or astigmatism visual axis), for the eye being tested (right or left eye).

This is important because to complete your reading, you must now measure your astigmatism axis in degrees, while first making sure that your phone is currently aligned along your astigmatism axis. You can re-rotate your phone 90 degrees, if necessary, using the exact same method as just described above. With the phone now  aligned along your astigmatism axis, simply find figure 2 (astigmatism target), and place the edge of the ruler, exactly vertical to you, and exactly through the center of the target, and read your astigmatism axis in degrees, directly from the degree scale on the outside of the target, where the edge of the ruler intersects the scale.

Also record, or write down, this measurement, on the initial answer sheet.

If any of your readings is less than 12″ from the screen, then you need to remeasure that reading on a table or desk in front of you (where the phone’s screen is initially around 12 ” from the eye being measured, using the detailed instructions below for a more accurate reading.

If you have  mild nearsightedness, and the red line is still in pretty good focus while overlooking the phone in front of you on a chair, try standing up while overlooking the phone, (or even place the phone on the ground to see if you can get the red line to blur). If it now appears blurry you can still make the same measurement, using the method just discussed above, or two measurements with the phone aligned along each of your visual axes if you have significant astigmatism.

If it is still in focus, then place the phone on the floor, propped up against the wall, 18 to 20 feet away from you, while now focusing on the inflexion point target (figure 2, maximally magnified). Slowly approach the phone until the vertical black line first becomes in focus, and appears at its widest, and doesn’t appear to change for 5 seconds after a double blink. Next measure from the tip of your toes to the phone’s screen along the floor, and record your measurement.  If you have astigmatism and both axes have very mild nearsighted refractive error, make two reading, focusing first on the vertical line, and next on the horizontal line, then record the largest numbered reading as your refractive error along your astigmatism axis, and the reading made closest to your phone as your spherical axis reading. The actual astigmatism axis in degrees can still be defined using the method just discussed for a normal reading above.

Brief directions for measuring a farsighted refractive error:

All farsighted reading should be made with your eye in a non-accommodative (non- focusing or relaxed) or partially accommodative state. This can quickly be determined just by observing the blur projecting off the red line.  If the blur is in a normal state for a reading, it will appear to  have have only one darker outer edge or line, and 2 or less darker lines within the blur itself. (If the blur has dark edges on both sides, or more than 2 darker lines within the body of the blur, continue pull and releases, at a distance ½ way between your SRD and the screen, until the extra darker lines within the body of the blur, or until one of the darker edges on the blur itself fades, and then you can perform a normal reading. Include multiple double blinks to reset your focus, as you perform these maneuvers. If you just can’t get your eye’s focus to relax, just perform the reading at another time of the day when your eyes are more fatigued.)

Most people have mild farsighted refractive errors which can also be measured by using the T thermometers at the top of the narrative. These measurements will be made at your standard reading distance, while overlooking the phone on a chair in front of you. First determine that a vertical white space,(CWS) is separating the projecting blurs, off the outside lines of the segment, from each other, somewhere within the center of the segment, on T9’s widest segment. If this is the case, you can use the following method to determine your refractive error. Your end point for your measurement, is finding the narrowest segment that is just wide enough to contain a CWS, separating the projecting blurs from each other, on T1 -T9.  If you have farsighted refractive error without astigmatism this is done with your phone exactly vertical to you. To determine if you have astigmatism or not, simply rotate the phone in both directions to determine if the CWS on an obvious CWS segment, is narrowing or even disappearing when rotating your phone in one direction, and is becoming wider and brighter, or the upper or nasal line associated with it is becoming darker, or at its darkest, when exactly aligned along your spherical axis, and your central white space at its brightest or widest along that same axis. Just as with the nearsighted reading you can rotate your phone 90 degrees, (by placing a ruler directly horizontal to you on the face of the phone, and then rotating the phone upward, so that now the ruler is exactly vertical to you), to realign your phone along your other visual axis, and determine the narrowest segment that is just wide enough to contain a CWS, and determine your farsighted refractive error for your astigmatism axis as well.  Likewise, the largest thermometer or widest segment reading will always be associated, when your phone is aligned along your astigmatism axis, which can allow you to determine your astigmatism axis in degrees using the astigmatism target also as described in the nearsighted section above. That is, with the phone aligned along your astigmatism axis, simply find figure 2 (astigmatism target), now place the edge of the ruler, exactly vertical to you, and exactly through the center of the target, and read your astigmatism axis in degrees, directly from the degree scale on the outside of the target, where the edge of the ruler intersects the scale.

The best method for making a farsighted reading on a specific segment to determine whether it is a CWS segment or a non-CWS segment will be described below. This method was developed to help your eye relax, or not over focus when making a reading.

  1. Begin your reading from your standard reading distance, while almost directly overlooking the phone, (with the phone placed vertically on the chair on  in front of you if you have no astigmatism, or two readings will be made with the phone aligned along each of your visual axes if you have astigmatism). Begin your reading of a segment, with an eye push up on a maximally widened segment. To perform an eye push up maneuver, first, place your fingers on the screen, and spread them apart, to maximally magnify the image. Next, by bending at the waist and moving your head towards the phone’s screen, slowly approach the phone’s screen while focusing on the CWS, or where you expect it to be located. Next, slowly move back to your standard reading position, while continuing to focus on the CWS as it usually narrows, and then once at your standard reading distance again, quickly remove your fingers from the screen to see if you can make the CWS disappear, defining that segment as a non-CWS segment.  If you can, just before you release the segment, and at the end of your maneuver, quickly evaluate if the blur now appears wider than the CWS, which almost always indicates the segment is going to end up being a non-CWS segment, or if the blur appears narrower than the CWS (almost always a CWS segment). Next, just go ahead and quickly release the segment to see if the CWS can be made to disappear, confirming the segment as a non-CWS segment. 
  2. If that doesn’t work, and a residual white space is still located just inside upper or nasal line after your quick release, then immediately after your eye push up, try a double blink or two, to see if that can make the CWS disappear, or several quick pull and releases, to see if you can make the CWS disappear after the quick releases. A quick pull and release, means briefly spreading the segment apart with your fingers on the screen, then quickly removing your fingers from the screen, to allow the image to snap back to its original size.
  3. Lastly, perform 3  slow eye push ups in a row with the segment maximally widened, bending at the waist and getting as close to the phone as you comfortably can, and then returning back to your standard reading distance at the end of each eye push up, and then quickly releasing the segment at the end of your 3 maneuvers, and if the CWS is still persisting, then define that segment as a CWS segment.
  4. A CWS can be quickly confirmed by being equal in brightness to the CWS in the segment just above it on the thermometer, and it will immediately start to push back the temporal or lower edge of the blur if you slowly start to re-approach the phone. If viewing a secondary white space (SWS) on a non CWS segment, a brighter white space will immediately appear, just inside the nasal or upper line, as you first start to approach the phone, now equal in brightness to the CWS on the segment just above it.
  5. Sometimes on horizontal readings, just by continuing to focus on the segment for 10 seconds or so, the residual white space may start to narrow and eventually blend into the blur, (especially on DE readings), as your eye’ focus relaxes, also indicating that the segment is still a non-CWS segment.

When recording your answer, count from left to right to determine your end point thermometer, and from bottom to top to determine the number of non-CWS segments on your end point thermometer to complete your reading. For example if the narrowest segment to contain a CWS segment, was on the 4th thermometer from left, and the 6th segment up from the bottom, record your answer as 0405 on your initial answer sheet for the specific eye being tested.

If the widest segment on T9 is a non-CWS segment, then read below on how to perform a true white space (TWS) reading using the wider T10 -T21 thermeters at the bottom of this narrative.  

Large farsighted readings (1TWS readings)

If T9 widest segment is defined as a non -CWS segment, then you will be determining the number of 1TWS segments on your 1TWS endpoint thermometer to determine your farsighted refractive error.

Normal NDE 1TWS reading:

1. Perform a deep eye push up on a maximally widened segment, and a quick release immediately following your eye push up. When performing the maneuver, focus on the border between the advancing inside edge of the blur and the CWS, to determine after completing the maneuver, (just after your quick release), if the residual blur is wider than the residual CWS (indicating the segment is likely a non-1TWS segment), or if the residual blur is obviously narrower than the residual CWS (then likely a 1TWS segment).
2. Next repeat the maneuver, this time performing a double blink immediately after you complete the push up back to your SRD, to see if the border between the two spaces, the blur and the CWS, merge together making it difficult to see where the blur ends and the CWS begins, (a non-1TWS segment), which can be quickly remedied by moving closer to the phone and seeing a distinct border between the two space suddenly present. If a distinct border remains between the two spaces after your double blink, then you are likely on a 1TWS segment.

Usually these two first maneuvers is all that is necessary to define the widest segments on progressively narrower thermometers as you move down the thermometers from T21 searching for your first non-1TWS widest segment.

If the first two maneuvers are inconclusive, especially when approaching your first 1TWS segment while working your way up your presumed 1TWS end point thermometer, initially defining lower, narrower segments as non-1TWS segments, then a more complete reading is indicted.

Complete reading:

3.Next, perform 5 eye push ups this time on a non widened segment. During the first 3 push ups, while focusing on the advancing inside edge of the blur where it borders the CWS, try and determine if the blur is wider than 1/2 the segment’s width as you complete the maneuver, (indicating most likely your are on a non-1TWS segment). On your 4th maneuver, perform a double blink, just after completing your maneuver, to see if the two spaces are merging as discussed above (also indicating that the segment is a non-1TWS segment). On your last eye push up, focus instead just inside the upper or nasal line to see if on a non-1TWS segment, a brighter 1TWS, (white halo or space), is emerging just inside those lines, after you first start to approach the phone, or even might disappear again as you complete your maneuver (also indicating that the segment is a non-1TWS segment, as opposed to a 1TWS being present at the beginning of your maneuver, persisting and often becoming more distinct as you perform your maneuver, and persisting after your maneuver on a 1TWS segment).}

Discussion (just repeating the above measurement in greater detail, if you already understand the directions, you  don’t need to read this, just use the above instructions to complete your reading):

      1. Your first goal for a 1TWS reading is to determine your 1TWS endpoint thermometer, which is the narrowest thermometer to still contain a 1TWS on its widest segment. Begin your reading on the widest segment on T21, and work downward. Again, test only the widest segment on the top of the thermometer, by first performing a deep eye push up on a maximally widened segment, while focusing on the border between the blur and the CWS, that is, on the blur’s leading inside edge, while performing your maneuver. After completing your eye push up back to your SRD, quickly release the segment, and AFTER your release, determine whether the residual temporal, or lower, blur is wider than your residual CWS after your quick release. If the residual blur is obviously wider than the residual CWS, its likely that the segment is a non-1TWS segment. Even when the blur appears to be wider than the CWS after your release, before defining the segment as a non-1TWS segment, you must always confirm that the segment is a non-1TWS segment, by repeating your first maneuver and performing a double blink immediately after your first maneuver, and by noting that the residual blur’s inside edge, merges into the upper or nasal residual CWS, making the separation between these two spaces indistinguishable, so that, often you can’t tell exactly where the blur ends and the CWS begins. When this is suddenly remedied just by moving slightly closer to the screen, where now a distinct, (often linear) border is now present between the two spaces, this confirms that segment as a non- 1TWS segment at your SRD. Likewise, for most readings, if you started on T21, then often the residual blur will be obviously narrower than your residual CWS, indicating that the segment is likely a 1TWS segment. Even on an obvious 1TWS segment, where the CWS is obviously wider than the residual blur, after your initial deep eye push up on the maximally widened segment, and your quick release, always perform a double blink immediately after your quick release, to see that the blur’s inside edge is remaining distinct, and now, while focusing on the blur’s leading inside edge, if you slowly approach the screen, it immediately starts to push back the temporal or lower blur. Next perform a single, or several, quick, shallow, pull and release while focusing just inside the nasal or upper line, to see that slightly brighter white halo, (1TWS), is present, and not disappearing after your quick releases, but instead was present at the beginning of your maneuver and was continuous and persisting after your quick releases, again quickly confirming the segment as a 1TWS segment, and allowing you to quickly move onto testing the next narrower thermometer’s widest segment.
      2. When you eventually get to segment that is narrow enough, that when you test the narrower thermometer’s widest segment, you might not be able to easily tell, after a single deep eye push up on a maximally widened segment, and a quick release, whether the residual CWS or the residual blur is wider than the other. Likewise, if you can’t tell for sure, whether the leading inside edge of the blur is remaining distinct, or is barely distinguishable, after your double blink, then move onto a more complete reading. On a 1TWS segment you should be able to tell exactly where the blur begins and the CWS ends even after your double blink, as you complete your maneuvers, which is provable by focusing exactly on that spot and seeing if the inside edge of the CWS, is pushing back the blur, as soon as you start to approach the screen, from exactly that same spot.
      3. To complete your reading, begin initially, by performing 5 eye push ups, on a non-widened segment this time. On your first 3 maneuvers, focus on the blur’s leading inside edge while you perform the maneuvers, and as the blur will often soften and extend further into the segment, as your eye’s accommodation relaxes during the maneuvers, try to see if the blur appears to be now to be extending beyond the ½ way mark as your complete your eye push ups, back to your SRD, indicating the segment is likely to be a non-1TWS segment. If the blur remains narrower than the residual CWS it is likely the segment you are testing is a 1TWS segment. On your 4th maneuver, perform a double blink after completing the eye push up, to see if the edge of the blur is now becoming indistinguishable, merging into the CWS, making it difficult to tell where the blur ends and the CWS begins, which can also allow you to define the segment as a non-1TWS segment. Lastly if the edge still appears to be distinct after 4th maneuver and your double blink; on your 5th eye push up on the non-widened segment, focus instead, just inside the upper or nasal line to see if a new brighter nasal or upper white space or halo, (1TWS), is presenting or emerging, as you first start to slowly approach the screen, which can still identify the segment as a non- 1TWS segment, (and although not necessary, to define the segment, which can be further confirmed if the 1TWS is disappearing again, after completing your push up back to your SRD).
      4. The presence or absents of a 1TWS just inside your upper or nasal line, can also be determined by performing a deep eye push up on a maximally widened segment, while focusing just inside your nasal or upper line, or while focusing on the residual slightly brighter white halo if one is present, (often brought out by maximally widening the segment), to note whether after your quick release, if the white space is disappearing indicating the segment is a non-1TWS segment, or persisting, instead, indicating that the segment is a 1TWS segment. As already mentioned, you can also confirm the segment as a 1TWS segment, at your SRD, with a quick, shallow, pull and release while focusing just inside the upper or nasal line, you should be able to make out a slightly brighter but often very faint white halo just inside the nasal or upper line which is more prominent as the segment is briefly widened, and also seems to be persisting after your quick release, confirming the segment as a probable 1TWS segment. It will be disappearing after your release on a non-1TWS segment. With this last maneuver, it is sometimes difficult to know for sure, if the brighter white halos are disappearing or not, because immediately after your quick releases, often ‘visual’ SWS are immediately replacing them as duller white spaces in the same location, rather than see them disappear completely, especially for DE readings. This still remains one of your best test however, for comparing your first 1TWS segment, directly to your last non-1TWS segment, where the 1TWS will be persisting on your first 1TWS segment, while disappearing after your quick releases on your last non-1TWS segment just below it. This is usually the last maneuver performed, just before counting the number of non -1TWS segments on your endpoint thermometer.
      5. Back to your reading, when you finally arrive on a widest segment, that is narrow enough to be defined as a non-1TWS segment, this usually defines the thermometer that is just wider than it, as your 1TWS endpoint thermometer, whose widest segment has already just been defined as a 1TWS segment. Now begin on its narrowest segment, and work upwards testing each of the segments, usually to initially identify those segments as non-1TWS segment using the same method of measurement as just discussed, until now you find a segment wide enough to be defined as your first 1TWS segment. When working the narrower segments, on your endpoint thermometer upward; anytime you perform an initial eye push up on the maximally widened segment, followed a quick release, and notice the blur to be obviously wider than the residual CWS immediately after your quick release, and then after a double blink, the leading inside edge of the blur, to become indistinguishable, where you can’t tell, where the blur ends and the CWS begins, immediately defines the segment as non-1TWS segment, allowing you to move onto testing the next wider segment. On wider segments where a complete reading is required, during your 5 eye push up on the non-widened segment, if the blur’s inside edge appears to become indistinct, merging into the CWS after your double blink on your 4th eye push up,  and a new brighter nasal or upper white space or halo, is emerging or suddenly appears, as you perform your eye push up, while focusing just inside the nasal or upper line on your 5th eye push up, then continue to define the segment as a non-1TWS segment, and move onto the next wider segment for testing. When the segment is wide enough that the blur initially appears to be narrower than the residual CWS, after your first maneuver and its quick release, and the blur’s leading edge is persisting, and appears distinct, after your first maneuver and a double blink, and after your 4th eye push up on the non-widened segment, and a double blink, as well, and no obvious new brighter white halo is presenting on your 5th maneuver, while focusing just inside your nasal or upper line, and your 1TWS is also persisting, on your other maneuvers as discussed above to verify the segment as a 1TWS segment, then you have just found your first 1TWS segment. To further confirm the segment, you can perform one, or several quick, shallow pull and releases while focusing just inside the upper or nasal line’s inside edge. On your last non- 1TWS segment you will see a brighter 1TWS is appearing as the segment is briefly widening, and then disappearing, or being replaced with a duller SWS, after quickly releasing the segment. On your first 1TWS segment the brighter white halo (1TWS) will be present at the beginning of your quick pull and release, and as you focus on it, will get brighter and more prominent as you widened the segment briefly, but will be continuous, and persist after your release as you continue to focus on it after your quick release. By counting your last non-1TWS segment and the ones below it, or narrower to it, you can complete your reading, that is, determine the number of non-1TWS segments on your 1TWS endpoint thermometer. For an example, after determining that 5 non-1TWS segment are on T17(endpoint thermometer), enter (fsprt=[1705]) in the fsprt  input box (just the number itself).
      1. After getting two answers the same twice in a row on two consecutive readings, enter your answers on the answer sheet, in the appropriate section.

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 Background information to help you complete your reading:

Identifying the type of refractive error each of your eyes have

  1.  Nearsighted (2a)
  2.  Nearsighted astigmatism (2b)  (where you are nearsighted along both of your visual axes)
  3.  Mixed astigmatism (2c), (where you are nearsighted along your spherical axis, and farsighted along your astigmatism axis),
  4.  Farsighted (2d)
  5.  Farsighted astigmatism (2e)

Example of a typical glasses Rx:

+5.25 + 1.25 x 180

-4.50 + 1.00 x 45

+2.50

+2.50

 

If you have an old Glasses prescription, the specific type of your refractive error can also quickly be determined, just from the RX, (as long as the second number is preceded by a plus sign). For each eye, a typical glasses Rx, may have up to 3 numbers in a row, from left to right, on Line 1, at the top of the RX, (right eye measurement), followed by up to 3 more numbers in a row, Line 2, just underneath the first line, which is your prescription for your left eye. If you are older than 40, you may have two additional numbers in the first column, underneath the first two lines, which represent your bifocal add, again with the right eye Add,  just over left eye Add (they are almost always the same number). The first number, on your first line, is your spherical power (sprt), which when using our technique, is measured with your phone aligned along your spherical axis, (or vertical to you, if your eye doesn’t have any astigmatism). If this is the only number present on line 1, this means you don’t have any significant astigmatism. If it is a positive number, (has a plus in front of it), then you have farsighted (2d) refractive error. If it has a minus in front of it, then you have nearsighted (2a) refractive error.

If you have astigmatism then all three numbers will be  present (on line 1 on your glasses RX), first, sprt, followed by, second, your astigmatism power, (aprt),  followed by, third, your astigmatism axis in degrees, (aart). During your actual readings, your aprt and your aart will both be determined with the phone aligned along your astigmatism axis. If again, the first number has a plus in front of it (+sprt), then you have farsighted astigmatism (2e) refractive error, (RE). If the first number has a minus in front of it (-sprt), and as long as that number is bigger than the second number, (+aprt), then you have nearsighted astigmatism (2b) RE. If the second number is the larger number, then you have mixed astigmatism (2c) RE.  For examples (using just line 1), nearsighted (2a) RE, (-4.00); farsighted (2d) RE (+3.00); farsightedAstigmatism (2e) RE (+3.00+1.00×180); nearsightedAstigmatism (2b) RE (-3.00+2.00×90); and mixedAstigmatism (2c) RE (-3.00+5.00×90).

If you can identify the type of refractive error that your eyes have just from your old glasses RX, as discussed above, go ahead and enter the specific type of refractive error for both of your eyes on the initial answer sheet. You can always change your answer, if you find that your type of refractive error has changed after your new measurements.

Normally,  just by viewing the instructional videos, or by reading the brief directions above, or by using both; should also allow you to determine the type of refractive error each of your eyes have, and complete your measurements for any nearsighted readings required, as well. In the end, both nearsighted and farsighted readings are very simple measurements, and once you are familiar with the measurements, can be made in a fairly, quick and accurate manner, (usually takes less than 10 minutes to complete for both your eyes, as demonstrated in the videos). We recommend testing your non-dominant eye (NDE) first, and then follow with a reading on your dominant eye (DE). Remember to enter, or record, your readings when required, on the answer sheet, at the time you perform your readings, so you won’t have to repeat any of your measurements, or at least write them down, so you can enter them later.

With careful measurements, this technique for obtaining glasses prescriptions can be just as, or even more, accurate than a subjective refraction at the eye doctor’s office.

(Disclaimer)

This exam only determines your refractive error, and does not substitute for an actual eye exam where physical problems of the eye and diseases can be diagnosed and managed. If in fact, you do have cataracts or corneal scars which create their own blurs, this method may not be accurate for measuring farsighted refractive error. Remember that making careful accurate measurements will lead to more accurate glasses for you, and in the end, better sight for you, as well. This technique just allows you to quantitatively measure your own blur from your own refractive error. Excepting for medical and physical problems with the eye, the amount of blur you have is directly related to the amount of refractive error you have, which allows us to determine your glasses prescription from your answers. (In other words, it is your responsibility to provide us with accurate measurements and information, which in turn, will allow us to provide an accurate prescription for glasses for you. As we can’t guarantee your input, we can’t guarantee the results of your input, but we will do our best to guide you.) There may be regulatory restrictions depending on where you live, which might prevent you from using your online glasses RX, to buy glasses locally, which may not be restricted by buying your glasses on line. This web site is trying to actively recruit licensed providers worldwide, as investigators of this new technique. Long term, our hope is, that once these investigators have tested and determined this new technique to be an accurate and reliable technique, their signed glasses RX will allow you to buy glasses locally in  what ever state or country you currently reside.

After you have had the chance to review the directions and the instructional videos, and feel that you have mastered this new technique, by practicing making measurements on your own eyes, and getting the same answers consistently, you will be ready to complete your final reading. You will be referred to a welcome page, ( https://onlineglassesrx.com/updated-rx/Welcome pagew.php  ), which will take you through the steps necessary to convert your measurements into an updated glasses prescription for you. This information can then be Emailed back to you.

(Materials needed: I-phone, tape measure, two chairs relatively equal in height, desk or table if available, and in addition, a 12” ruler is also helpful).

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(Although it is easier to read the narrative with the phone width wise; when making readings on visual targets, make sure to start your measurements with the phone vertically oriented on a flat surface, (and initially with the images maximally magnified), and then to rotate the phone on a flat surface for your horizontal readings (to preserve the correct size of the images.)  Also, readings should not be made within 15 minutes of waking up, or if you are too tired or sleepy to perform the readings, because it can affect the accommodative state of your eyes being tested, and the accuracy of your readings. For nearsighted reading, it is best to perform these nearsighted readings in the morning about 30 minutes after waking up when your eyes are refreshed and relaxed, and for farsighted readings in the late afternoon, or early evening, when your eyes are a little more fatigued.)

Identifying dominant and non-dominant eyes:

 

 

 

 

 

 

 

 

To identify which of your eyes is your dominant eye (DE) or your non- dominant eye (NDE) (usually on the same side as your dominant or non-dominant hands), you can use the following method. Make a little triangle by folding your hands together, (as shown in the picture above). Then holding your hands about 12” in front of your face, place any small distance image in the center of your triangle. If you automatically closed one of your eyes to do this, the eye you have remaining open is your dominant eye; or by closing one eye at a time, when you close your non- dominant eye the object you selected will remain in the center of your triangle, where it will usually move outside your triangle if you close your dominant eye. (If you can’t voluntarily wink or close one of your eyes, just make a circle with one hand, holding your make shift telescope, 6” to 12” in front of you, and then place any distant image in the center of your circle, now using your free hand to cover one eye at a time, identify your dominant eye by covering your dominant eye and noticing that the image you have selected is now outside your circle).

Enter your answer to identify, DE=Rteye, or DE=Lteye, in the input box on the initial answer sheet {form0.php (initial answer sheet)}.

We will begin your reading by measuring your NDE first, and then follow with a DE reading. From this point on, the eye you are measuring will just be identified as either your left or right eye. When entering your answers, the actual eye being tested will be also identified, by a rt or lt attachment, at the end of whatever measurement you are making, (for example, sprt for a spherical power reading on your right eye, or splt for a spherical power reading on your left eye).

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Figures 2: 10 Degree Astigmatism Target

 

 

 

 

 

 

 

 

 

 

 

Figure 2: 10 Degree Astigmatism Target

 

Figure 3: Inflexion point target

 

 

Standard reading distance(SRD):

Your standard reading distance will usually be made from about 15.0 to 17.5 inches (38 to 44.5 cm) from the phone’s screen. This can be achieved by placing your phone vertically, on an identical chair, (in height at least), to the one you are sitting on, with the other chair being about 10 inches (24.5 cm) or so in front of you. Now, lean over the phone, with your feet flat on the floor, just outside the chair, and your elbow resting on your leg, (in a straight full extension of your leg) near or at your knee, and your head resting on your open hand, ideally with the outside of your index finger (1st finger next to your thumb) touching your eye brow, and the outside of your thumb touching your cheek bone just below your eye, as if your face was resting on your hand which was in an extended open curl, (and as if your index finger and thumb was holding one of the lenses on your glasses, in front of your eye being tested, with your other eye closed), when looking almost directly over the phone’s screen at the images.

Don’t need to read:

Reference section only (if you need more detailed instructions)

Category or Type of refractive error:

Determining the type of refractive error (RE) each of your eyes have:

First, scroll to the top of this narrative, and find figure 1, (T thermometers). Maximally magnify the image on your phone’s screen. Begin by focusing on the narrowest thermometer T1, and on its widest or top segment, and then focus only on the top segment’s vertical red line. Now place the phone exactly vertical to you, on the chair in front of you, while almost directly overlooking the phone, support your head with your hand, and your arm with your knee, feet flat on the floor outside the chair, so that the phone is about 15-16 inches away from the eye you are testing, with your other eye closed or occluded. Again, we call this your standard reading distance (SRD).

If the red line on T1’s top segment is still in pretty good focus at your SRD, and remains in pretty good focus even after sitting straight up and overlooking the phone, but you know your vision is blurry at distance, then most likely you have either mild or very mild nearsighted refractive error. If this is the case, make sure you read the mild nearsighted refractive error discussion in the brief instructions above.

Assuming, that the image is blurry at your SRD, (normal reading), next we will determine if you are overall nearsighted or farsighted at you SRD. (Again, after starting at your SRD, while closing one eye, so that only one eye is being tested at a time), begin by scrolling to wider thermometers, to find one that is just wide enough, that a vertical central white space (CWS), appears, separating the two projecting blurs off the red and blue lines from each other, within the segment, or often separating the blur projecting off one of the lines towards the center of the segment from its opposing line and its blur projecting symmetrically in the same direction, outside the segment. Just by noticing if the CWS is located just inside the temporal line (the line located closest to your temple from the eye you are measuring), means most likely you are nearsighted overall, and if the CWS is located just inside the nasal line (the line closest to your nose), then most likely you are farsighted.

To confirm that you are nearsighted, move closer to the screen to see if the lines are becoming in better focus, that is, the blurs projecting off the lines are narrowing, and the CWS is widening. Stop at that distance from the phone where the lines appear to be in their best focus, and at their widest, that is, where a small incremental movement towards the phone makes the red line appear to narrow or blur slightly, or move slightly away from you, or outward; or if focusing on the projecting blurs, that distance from the phone, where the projecting blurs widen slightly if you move slightly closer to the phone, and the same thing happens if you move slightly away from the phone. Next, at that distance, (just described above), from the phone, where the lines appear to be in their best focus, and appear at their widest or closest to you, or the projecting blurs at their narrowest, rotate the phone to the left and then to the right, around 45- 85 degrees, to see if you have any astigmatism or not. If the image changes slightly, but looks the same when the phone is rotated in either direction, and appears to stay in pretty good focus, then you probably don’t have significant astigmatism, and have just nearsighted refractive error (2a). If the image becomes in better focus when you rotate the phone in one direction, while it becomes more blurry when you rotate the phone in the opposite direction, then you have nearsighted astigmatism (2b), or mixed astigmatism (2c). If you have nearsighted astigmatism(2b), or mixed astigmatism (2c), you can also get the line into perfect focus, eventually by adjusting both your distance from the phone, and by rotating the phone in the direction where the line was becoming in better focus, until the phone is exactly aligned along one of your visual axes. When this happens, a slight rotation in either direction off your visual axis, causes the line to narrow or blur slightly. Any eye with astigmatism, will have two visual axes, an astigmatism axis (when your phone is aligned along your astigmatism axis, where a neutral point will be measured at its furthest distance from the phone’s screen) and a spherical axis, (where neutral points will become in focus at their closest distance to the phone’s screen, with your phone aligned along your spherical axis). They will be located 90 degrees from each other. When the red line becomes in perfect focus after adjusting both your distance from the phone, and aligning the phone along one of your visual axis, the distance from the bony corner of your eye to the phone’s screen, is called your neutral point, for that specific visual axis. At your neutral point, your nearsighted refractive error has been neutralized by adjusting your distance to the screen, and your astigmatism refractive error has been neutralized by exactly orienting your phone along your visual axis, which eliminates that blur as well. To distinguish 2b from 2c, and to determine whether your original visual axis (the visual axis with the least amount of refractive error) is your astigmatism axis or your spherical axis; we are going to rotate the phone 90 degrees to be aligned along your other visual axis. To do this, place a ruler exactly horizontal to you, centrally on the phone’s screen, and then by rotating the phone, always upward, to make the ruler now exactly vertical to you, you have rotated the phone exactly 90 degrees to be aligned along your other visual axis. Usually if you have nearsighted astigmatism(2b) you should now be able to get the red line in perfect focus by moving closer to the phone, which confirms that the phone is now aligned along your spherical axis, and that originally it was aligned along your astigmatism axis. If instead the line only becomes in perfect focus when you move further away from the phone, it still means you still have nearsighted astigmatism(2b), but it also means that your phone is currently aligned along your astigmatism axis, and your original axis was your spherical axis. If the red line never becomes in perfect focus, but remains blurry at any distance from the phone, it means you are likely farsighted along that axis (your astigmatism axis), and that you have mixed astigmatism(2c) refractive error, and your original axis was your spherical axis. This can be quickly confirmed, by moving back to your SRD, and noting the CWS is now located just inside your nasal line, and that it is staying about the same width or even widening as you slowly approach the phone’s screen, which distinguishes it from a mild nearsighted refractive error, where the CWS would be narrowing as you approach the phone’s screen. Once you have distinguished which visual axes is your astigmatism axis, now, with your phone aligned along your astigmatism axis, you can quickly determine your astigmatism axis in degrees, by first scrolling down to (Figure 2: 10 Degree Astigmatism Target); and then by placing a ruler or straight edge directly through the center of the target, and exactly vertical to you, and reading your astigmatism axis in degrees, directly from the scale on the top of the target, where the edge of the ruler intersects the scale. Remember to record your answer, (just the number), in the input box for aart or aalt on the initial answer section, depending on which eye you were testing, or at least, write it down, so you can enter it later. Next, we would like to begin our neutral point readings by initially measuring your spherical power with your phone aligned along your spherical axis. For (2c) and (2b) eyes, if your phone is currently aligned along your astigmatism axis; to rotate your phone 90 degrees back to your original spherical axis, again just place the ruler exactly horizontal to you, always rotating the phone upward, until it is exactly vertical to you again, and the phone will again be aligned along your spherical visual axis. These measurements will be described in more detail in section 1, and on the instructional videos.

If instead, your CWS is located just inside your nasal line, to confirm that you have farsighted refractive error at your SRD, you can also, move either towards, or away from the phone’s screen, to note that the CWS stays about the same width, or even widens as you move towards the screen, and although the line may get easier to see, never become in clear focus at any distance from the screen, (always has a blur projecting off the red and blue lines). Often the CWS will disappear completely when moving away from the screen. Likewise, you can test for astigmatism by rotating your phone, 45-85 degrees, in either direction as well, and by focusing on the CWS. If the CWS narrows or even disappears when rotating your phone in one direction, (towards your astigmatism axis), and widens or becomes brighter and more defined, while the nasal line adjacent to it becomes at its darkest along a very narrow range, with the phone aligned exactly along your spherical axis, then you have farsighted astigmatism (2e), and have just aligned your phone along your spherical axis, where the lines appear to be in their best focus, at their narrowest and darkest, at your SRD. If the CWS stays about the same width when rotating the phone in either directions this means you have farsighted without significant astigmatism (2d).

 

Section 1 Nearsighted measurements:

Making a normal nearsighted (sprt or splt) measurement:

If you your eye has nearsighted without astigmatism refractive error(2a), you should be able to get the red line into perfect focus and at its widest, just by adjusting your distance from the phone’s screen, with the phone aligned exactly vertical to you. The same is true for (2b) and (2c) readings, having aligned your phone exactly along your spherical axes. If your neutral point appears to be greater than 10.5 inches or further from the phone, this can be done by beginning far enough from the phone’s screen that the red line is clearly blurry, (usually at a sitting straight up position for a normal reading). Next, make tiny incremental movements towards the phone’s screen, initially noting that the red line should appear to become in better focus and appear wider in response to each small movement forward. Blink once or twice between your small movements forward to reset and relax your focus. Eventually, when you make a small movement forward and this time the line appears to move slightly away from you, or outward, or even blurs or narrows slightly, then you have reached your endpoint for making a measurement. Move back to your neutral point where the red line was at its widest, or appeared to be at its closest to you, and repeat the same small movement forward to make sure you get the same response. Next move slightly away from the screen from your neutral position, to also see that the line appears to move slightly away from you or narrows slightly, which helps confirms your neutral position is correct. Return back to your neutral point. (If instead it widens and gets in better focus when moving back away from your neutral point, continue making tiny incremental movements backward, until it appears to move further away from you, or narrow, or blur slightly, that is, your eye’s accommodation has relaxed, and then test and confirm this new neutral point, and then make your measurement from there). Lastly, to confirm your neutral point, perform a double blink to reset your focus, while at your neutral point. If you are exactly at your neutral point the line you are focusing on should remain in good focus with your eye relaxed as you continue to focus on the line for 5 seconds, specifically the line should not fluctuate in its appearance or start to narrow as you continue to focus on the line over that 5 seconds, if it does it usually means you have moved beyond your neutral point (too close to the phone). If this is the case, move further away from the phone until the line is clearly blurry again and then re-determine your neutral point. When it passes this final confirmation, (the image remains in focus, does appear to fluctuate in its appearance or narrows as you continue to focus on the line for 5 seconds, after a double blink, and while your eye remains relaxed (or feels like it isn’t trying to keep the image in focus for you), then measure and record your answer. To make a measurement at your neutral position, (and while holding your head very still, and wrapping your 4th finger around the base of your tape measure, touching the outside bony corner of your eye to keep the tape measure flush, while lying flat along your temple), measure from the outside bony corner of your eye to the phone’s screen to determine your spherical power for your nearsighted refractive error, in inches, (to the nearest 1/32 of an inch), or in millimeters. Record your answer after getting two answer the same, after making two measurements twice in a row, (that is, where no adjustment needed to be made in your locked tape measure, from the previous reading).

For neutral points from 10.5” to 5.5” from the screen, “desk” measurements need to be made. “Desk” readings are made with the phone first moved to a desk, or table, or a stack of books, so that the phone is beginning about 12” away from the eye being tested. The phones orientation along a specific visual axis can be maintained, by placing a ruler centrally on the phone exactly vertical to you, moving the phone to the desk with the ruler still exactly vertical to you, without moving the ruler during the move. The phone should be aligned exactly vertical to you for a 2a reading, or aligned usually initially along your spherical  axis for a 2b or 2c reading, while almost directly overlooking the phone during your reading. For these readings, neutral points are determined by where the red line first becomes locked into clear focus, and where the line’s appearance doesn’t change at all, (specifically, that the lines width does not narrow at all), as you continue to focus on the line for 5 seconds after a double blink, with your eye, and its focus, remaining relaxed over that same 5 seconds. This is opposed to your eye continuing to try and keep the line in focus for you, causing the line to fluctuate in its appearance, or in its focus, often narrowing as the eye accommodates, letting you know that you are not at your exact neutral position. If this is the case, then you need to repeat your reading, again, starting out far enough from the phone, that the line appears blurry again, and re-approach the screen, until you can lock the line into focus, and this time the line holds its focus, after a double blink and viewing the line for 5 seconds, (specifically that the width of the line, does not appear to change at all, while your eye remains relaxed).

If your neutral position is closer than 5.5 inches from the screen, often your neutral point can be identified when the pixels first become in focus, in response to a tiny movement forward, that is, present as longitudinally lighter and darker lines within the width of the red line, or even in a checker board appearance, with the edge of the line well defined and straight as well. If you can’t get the edge of the line to be straight and well defined, as well, (when the pixels first present), try realigning your phone to be exactly aligned along your visual axis again.

Neutral point measurements are always made holding your head very still while measuring from the bony outside corner of your eye to the phone’s screen, and after locking the tape measure, and then by repeating the reading from the beginning, and getting the same answer twice in a row, where no adjustment needs to be made when re-measuring with the same tape measure. As a rule, use T1’s narrowest segment’s red line to focus on for a vertical reading, and T6’s widest segment’s red line to focus on for horizontal readings. Usually during these readings, your eye being tested, should be opened as wide as it will go, to suppress your eye from accommodating, while remembering to blink once or twice, in between your small incremental movements forward, until you have reached your endpoint for determining your neutral point. As always, the repeat measurement starts far enough out that the lines are clearly blurry, usually from a sitting straight up position for “chair” readings, and from about 12” from the screen for a “desk” reading, recording your answers after getting two measurements the same twice in a row. If you are measuring very mild nearsighted RE, take either small slow steps forward, or just move your head forward several inches to assess the images response, in between small steps forward to eventually find that same end point.

Your neutral point measurement will give you the value of your nearsighted spherical power, (nsprt or nsplt) depending on which eye you measured, and that your phone was aligned along your spherical axis for a 2b or 2c reading.

(Enter your answer for a nsprt or a nsplt reading, (in inches) in the input box for a nsprt or nsplt reading on the initial answer sheet, If you measured in mm, make sure to label your answer in mm, or if you want, divide that number by 25.4, and enter this new value in inches. If you measured in inches, for example if your neutral point was measured at 7 12/32”, first divide 12 by 32 to obtain a decimal (out to 4 digits), and then add this value to 7, (7.375), enter nsprt=[7.375].(enter just the number in the input box)

Making a normal nearsighted (Aprt or Aplt) measurement:

Start by rotating your phone 90 degrees to now be aligned along your astigmatism axis (where the red line is in perfect focus at its furthest distance from the phone). Again, this can be done by placing a ruler exactly horizontal to you, centrally on the phone’s screen, and then rotating the phone, always upward, to make the ruler now exactly vertical to you. Using the same directions above for making a normal nearsighted reading, once identifying your end point for measurement, and then make a neutral point reading by measuring from the bony corner of your eye, to the phone screen, with a tape measure. Record your measurements as directed, after getting the same answer twice in a row, that is, where no adjustment is needed, after having locked your tape measure after your first reading. If any of your AP neutral point readings are further than 10.5 inches to the screen, you will need to relocate your phone to the chair in front of you, for a normal “chair” reading as just described above. This can also be done by placing a ruler centrally on the phone exactly vertical to you, moving the phone to the chair with the ruler still exactly vertical to you, without moving the ruler during the move. This reading will allow you to determine your astigmatism power (naprt, or naplt) in inches (to the nearest 1/32 of an inch) or in centimeters (to the nearest millimeter), which you can easily convert to inches, up to four decimals out, as just discussed above for your nsprt, or nsplt measurements.

Enter your answer (number only, up to 4 decimal points) in the naprt or naplt input box on the initial answer sheet. Using the example above, for a measurement of 7 12/32” or about 18.7cm or 187mm, naprt = ‘7.375’ in inches or naplt =‘7.375’ in inches.

With your phone now aligned exactly along your astigmatism axis, we can also scroll down to figure 2, (astigmatism target), and determine your astigmatism axis in degrees, (aart or aalt), by placing a ruler or straight edge directly through the center of the target, and exactly vertical to you, and reading your astigmatism axis in degrees, directly from the scale on the top of the target, where the edge of the ruler intersects the scale.

For an example if your astigmatism axis was measured exactly at 180 degrees, Enter aart =[180] or aalt =[180], in the aart or the aalt  input box, on the initial answer sheet, (again, enter just the number in the box).

Next by repeating your measurements for your other eye, using the same directions, we can complete your readings for nearsighted(2a) and nearsighted astigmatism(2b) clients. Mixed astigmatism(2c), and farsighted clients (2d and 2e), will be given directions for making a farsighted measurements, (in section2),  to define their farsighted spherical and astigmatism power values(Ex. fsprt, faprt, fsplt, faplt).

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Section2 Farsighted measurements:

(Your farsighted glasses reading will change if you perform your reading in the morning, or in the evening, you will select a higher farsighted treatment RX in the evening, because your eyes are more tired. Perform your reading at the same time, when in life wearing your glasses is most needed; or if you need your glasses all the time, it is best to perform your reading sometime in the afternoon, or early evening.)

As already described above, most farsighted refractive errors can be determined by counting the number of non-CWS segments on your CWS endpoint thermometer (the narrowest T- thermometer, that is just wide enough to contain a CWS on its widest segment), on T9 and below.  For larger refractive errors, the number of non-primary true white space segments, (non-1TWS),  on your 1TWS endpoint thermometer, on T10 and above, can be used instead, to determine your farsighted refractive error. A 1TWS is a thin bright white halo that appears just inside your upper, or nasal lines, with your phone aligned vertically for a 2d reading, or aligned along one or both of your visual axes for a 2c, or 2e reading. For vertical readings, it only occurs on segments that are wide enough, that after performing a deep eye push up on a maximally widened segment, and AFTER its quick release, the residual CWS is found to be wider than the residual blur, (that is, on CWS segments, where, the CWS occupies more than 1/2 the segment’s normal width). It can be easily recognized, by being obviously brighter than the CWS, or any SWS (secondary white spaces created by visual processing, if present), which are also located just inside the upper or nasal lines, and by the presence of a distinct border, after a double blink, between the CWS and its opposing nasal or upper leading edge of the blur, which doesn’t occur on non-1TWS segments.

If your CWS endpoint thermometer was on T9 or below, then you will be making a CWS reading to determine your farsighted refractive error with the phone exactly vertical to you for a farsighted(2d) reading, or with the phone aligned along both your spherical axis (fsprt or fsplt) and then your astigmatism axis (fsprt or faplt) for a farsighted astigmatism(2e) reading, or aligned along just your astigmatism axis (faprt or faplt) for a mixed astigmatism 2c reading. Use the brief instructions above to compete your reading.

If your CWS endpoint thermometer was on T9 or above, you will be making a 1TWS reading on T10-T21 to determine your farsighted refractive error for these higher refractive errors.

Video of a CWS reading on T2-T6:

https://youtu.be/1T0uQifd8GQ

(By viewing this video, although this describes an older method of measurement, you will be introduced to the basic techniques, and tools (T- thermometers), used in measuring your farsighted refractive errors, a deep eye push up on a maximally widened segment, a pull and release maneuver, and an eye push up on a non-widened segment). These maneuvers are also described in greater detail in the reference section towards the end of this narrative.

 

A CWS measurement has already been described above.

 

Special case: (T1 is your CWS endpoint thermometer)

(When your CWS endpoint thermometer, while aligned along one of its visual axis, or aligned vertically, (if no astigmatism is present), appears to be T1, (that is T1 widest segment appears to be a CWS segment); the standard indirect reading, becomes a two- step method for most readings, first a deep eye push up on a maximally widened segment, followed by 4 quick pull and releases, to see if the CWS is persisting (CWS segment) or is disappearing on a non-CWS segment. When performing a T1 reading, if the CWS narrows or even disappears as you move towards the screen, (using an eye pushup on a non- widened segment), this usually indicates that you are, in fact, mildly nearsighted at distance (mild 2a, mild 2b, or mild 2c), along the axis that your phone is aligned with, as opposed to the CWS staying about the same width or even widening, if you are farsighted at distance.  This is true even if you are farsighted at near, at the same time, just from being over 40. If this is the case, use the directions for mild nearsighted refractive errors, (located just above and including section 1), to complete your reading. If you are normally nearsighted at distance, and farsighted at near from being older than 40, and all the segments on T1 are CWS segments just use direct nearsighted “chair” readings to determine your nearsighted refractive error at distance.

If you are older than 40, and have enough farsighted at near refractive error, along either of your visual axes, just from being older, so at least, the bottom segment on T1 is a non- CWS segment, then you also have an option of  performing a normal farsighted reading (determining the number of CWS segments on T1, at your SRD), and determine your farsighted refractive error at near, as well. (You can scroll down to section2 for specific directions). Your farsighted at near reading can indirectly determine your nearsighted refractive error at distance also, or at least give you a very accurate estimate. Since it is an easier and more comfortable reading to make, it may be one of your few advantages of being older.

Or better still, you can measure both, which will give you an actual measurement for your farsighted at near refractive error, as well as, your nearsighted at distance refractive error.

If all the segments on T1 are CWS segments, and you are not nearsighted at distance,  you don’t need glasses.)

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T10       T11       T12

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

T13      T14         T15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

T16         T17           T18

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

T19            T20             T21

 

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