Easily Check Your Diopter¬†Numbers.
In many respects this calculation is more accurate and relevant than computerized photoropter measurements at the optic shop, and even more detailed than looking at a Snellen chart.
Centimeter Calculator Version 0.1
1. ¬†Take off your glasses.
2. ¬†Use the instructions to find where the text on the screen just barely starts to blur.
3. Measure the distance from your eyes to the screen at this “blur-distance”.
4. Enter your current diopters¬†(optional).
5. Enter the ‘blur-distance’.
The calculator will now show you your correct diopters.
–> Next: Go To The Calculator Here.
You will also want to read this further explanation of how to do centimeter measurements, correctly: ¬†Centimeter How To
*Best font size? ¬†12 points. ¬†Or for a more detailed explanation, see here.
How Does It Work?
It simply calculates diopters (diopter being nothing more than inverse meters). ¬†The variance is how you look at the ‘edge of blur’. ¬†Important to note here is that you want to be where things are still clear, but another half centimeter further away, you notice a loss of sharpness. ¬†This requires a little bit of experimenting.
You can also look at your current diopter¬†values, and the related centimeters – so now you can get that exact distance to the screen and see how sharp the image is (without wearing glasses). ¬†How much can you move backward from your centimeter equivalent of diopters? ¬†If you can move back and still see sharply, you’re over-“prescribed”.
Be sure to keep a log of your measurements. ¬†Especially if you are participating in BackTo20/20, you will want to know where you started, and how much you are improving. ¬†Read this topic about keeping a log.¬† Also, for a better understanding of why your prescription is quite damaging when you use it for close-up work, take a look at an explanation of the blur horizon.
We discuss the topic of excessive diopters¬†and it’s contributing effects to worsening myopia in various parts of the site and as part of vision improvement strategies.
Take a look for example at ‘Snellen is not a fixed number” or the (somewhat lengthy) explanation of myopia: ¬†Understanding Myopia.
Click the link below to be taken to the centimeter calculator.
Take a moment to read the instructions. It takes a small measure of patience to find your values the first time – quite worth it! You can easily check your diopter¬†value, and the degree of changes throughout the day.
Got High Myopia? ¬†Check out this awesome, free DIY solution: ¬†http://endmyopia.org/brilliant-diy-centimeter-measuring-tool/