Jump to navigation Jump to search
The cm measurement uses a basic optics formula to calculate the diopters of correction you need to see clearly long distance.
- Hold a ruler up to your eye, and measure how far away you can still read text without blur in centimeters. This is your "cm measurement".
- The ideal precise measurement is from the surface of your eyeball, but this is obviously not safe, so measure from some facial structure near your eye.
- Consistency is more important than accuracy, you want to be able to track your small changes over the course of a day, and larger changes over time.
- Calculate diopters from the measurement: Diopters = -100cm/cm measurement.
- If your result is stronger than -4D, and you wear glasses, you'll need to correct for vertex distance to convert this from contacts diopters to glasses diopters.
- If your result is stronger than -10, you'll likely have problems getting consistent readings.
- EndMyopia Diopter Calculator
- Varakari's Vision Log Tool
- The iOS Sight Meter App
- The Android Diopter Calculator