Checking Eyesight-Distance with Ruler and Cupboard

Hi,
I had problems checking my exact eyesight with certainty and always thought about an easy setup how to do it. (With Jake’s easy method with printing out the ruler and hold it to the eye I could not do it with certainty, I also tried the app with camera but was not really satisfied.)
So I figured out today this method and wanted to share with you. You need a real plastic ruler and something, where you can stick it in, I used the doors of my cupboard, they work perfectly with holding the ruler.
Then you can define which part of your face can touch the ruler (I prefer my nose), while checking your focus distance. It should be the softest touch you can do, no pressure at all. It is important the ruler can’t move while checking and the focus paper should be completely flat.
I use a 30cm ruler, because I have high myopia. Maybe this method won’t work if you have low myopia, because you would need a long ruler which would be too heavy to stick in something.
Of course you need to add the distance from your eyes to your nose (in my example) and maybe leftout areas in the ruler (from edge to 0 cm start) to the checked ruler distance in order to get the right cm distance.

Now since the eye doctor checks only the 0.25 steps, and nothing smaller than that, you should only compare these 0.25 step distances with the ruler and nothing smaller than that (because it is probably too small to be sure). So for my eyesight between -4.5 and -5.5, every step is basically nearly 1 cm.

I found out I have astigmatism, I see horizontal lines worse than vertical lines so I think it is useless to look at mixed structures like letters etc, it makes more sense to look at lines.
So my best method finding the edge of blur now is starting at a high distance and checking until I see the barcode without any double vision blur. I check my eyesight with vertical lines, because these are also the ones I see on Snellen chart. Horizontal lines I see worse because of astigmatism. This discovery is very important for me.
So my advice is check first, if you have astigmatism with the 2 test pictures at the bottom (if you have you will see some lines unclear), afterwards you can decide which lines you choose for checking the edge of blur distance (choose the lines you see without astigmatism clear).
I added 2 additional distance holders (position 1 and 2) to the ruler in 1 cm steps, so I can simple move my nose to them without moving the ruler for every centimeter, highly recommended.







hornhautverkruemmung-strichkreistest

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In my opinion it doesn’t matter getting the exact precise measurements as long as you are measuring the same way every time, so you can see long term cm gains even if the cm themselves dont correspond to your correct diopter value.

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Yes, but for me it is even hard to make reproduceable measurements. Even finding always the same edge of focus distance is difficult, because I am not sure, is the distance really sharp or a little blur.
In fact the word “measure” is wrong and misleading, you can’t measure your eyesight exactly. It should be called “check your eyesight-distance” with defined distances (-5 = 20cm, -4=25cm,…).

Just in case, I ordered a test lens kit anyway, which will give much more advantages. I think endmyopia should state that very big:
“BUY A LENS KIT! THIS IS A MUST HAVE!”

It’s only in the beginning. After you established your first normalized then you have no use of the lense kit. Or maybe if you have high astigmatism.

By the way I found that cm measurements is not that useful for middle-high myopia (above about 35-40cm), because there are just too small distance changes to 0.25 dioptre changes. I like checking Snellen chart much more useful in this range.

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I am having problems with the Snellen chart. The one I printed out from Endmyopia does not have the same actual letter size when printed out, or the same gradations as another one I found online. Check out this one,and compare it with the one provided by Endmyopia.


The differences are not insignificant, and I have been over-estimating my visual acuity on the Endmyopia one. I have now ordered a 6 m Snellen chart online, and hope that this one really does give the correct scale and letter size. Fortunately I have a very large room (converted barn) which could accomodate a 10 m Snellen chart if necessary. I know that it is the relative improvement that matters, but as I am still having difficulty determining my diopter needs, initially I would like a more accurate standard to measure against. If, as you say, cm measures for anything over 35-40 are not very useful and my stronger right eye measures at 38-40 depending on light and time of day, I will need an accurate Snellen chart to confirm.
Have you any idea on how useful a hand-held Snellen would be for measuring high myopa? I find cm measuring for a highly astigmatic and myopic left eye very challenging as well.

p.s. I have just checked my online order, and the gradations on the chart I ordered correspond with the Endmyopia one, so I don’t know where the above posted chart got its gradations from. In any case, I will need a sturdy plastified chart to take to India with me.