Eye Chart: Snellen & Amsler

Want a familiar eye chart on your own screen for screening practice? MoonOptic sizes Snellen-style letters and a tumbling E with a ruler, and adds an Amsler grid and a simple results list.

CALIBRATE ONCE
Match the black line on screen to 50 mm on a ruler. Every line of the chart is then drawn at the size that fits the distance you pick. Change the screen width and the app asks you to measure again.

CHOOSE HOW YOU READ
• Distance: 1 m, 3 m, 10 ft, 20 ft or your own step
• Right eye, left eye or both eyes, with a reminder to cover the other one
• Letters or tumbling E; Shuffle changes the letters and the E direction
• Lines 20/200 to 20/20 with the letter height in mm
• White or black chart, full screen, bigger / smaller, optional 10-second steps
At long distances a line that is wider than the screen shows fewer letters at the same size instead of smaller letters.

AMSLER GRID
Cover one eye, look at the center dot and check the grid for wavy, blurred or missing lines.

YOUR RESULTS
Record the smallest line you could read together with the eye and distance. The results page shows the smallest line you recorded for each eye and distance plus the full list by date, and you can delete entries you don't need.

The calibration and your chosen distance are kept for next time on the same screen size.

IMPORTANT
This app is for screening practice and your own notes. It is not a diagnosis, does not measure your prescription and does not replace an eye exam. See an eye care professional if your vision changes suddenly or you have pain, flashes or new distortion.

This app is not a medical device and does not diagnose, treat, cure or prevent any medical condition. Consult a healthcare professional for medical advice, diagnosis or treatment.