Optometry Fans - Duochrome Test

Duochrome Snellen Test

Comparing letter clarity across red and green fields for spherical correction.

RED FIELD GREEN FIELD

How to Perform & Interpret

1. Performance Checklist

1. Ensure Size: The chart should fill a good portion of your screen (try full-screen mode).
2. Isolate Eyes: Cover one eye completely and test the other eye first.
3. Find Best Line: Look at the smallest line of letters you can *almost* clearly distinguish.
4. Compare Clarity: Determine if the letters on the **RED** side or the **GREEN** side are **clearer** and appear **darker/sharper**.

2. Interpretation

If the RED side is clearer:

You are likely **undercorrected** (you may need more minus power, meaning your prescription is too weak for myopia/nearsightedness).

If the GREEN side is clearer:

You are likely **overcorrected** (you may need less minus power, meaning your prescription is too strong for myopia/nearsightedness).

If both sides are **equally clear**:

Your spherical correction is **optimal**.

Disclaimer: This test is a simulation and not a substitute for professional eye examination. Consult an eye care professional for accurate diagnosis.