The Chameleon Test
A chameleon is hiding in the stained glass window. Tap it as soon as you see it. Screen after screen, it blends in better and better with the reds, greens and blues, until your eyes can no longer tell it apart.
- Duration
- about 1 min 30
- Answer
- one tap per screen
- Measures
- L, M and S cones
At the end of the test, only your perception thresholds, the result and the screen type are saved. No name, no account, no cookie, no IP address, no ads. No commercial purpose: this data is only used to better understand color vision and to make this test more accurate.
This test is indicative and depends on your screen settings. It does not replace an exam with an orthoptist or an ophthalmologist.
Three settings for accurate colors
- Turn off night modeNight Shift, True Tone, blue light filters or reading mode turn the screen yellow and mostly distort the blues.
- Turn the brightness upThree quarters or more, with no direct sunlight on the screen.
- Take off tinted lensesSunglasses or color-correcting lenses. Keep ordinary prescription glasses on. Sit about 50 cm (20 in) away.
Let your child search alone, without pointing it out. If they can't find it, they press "I can't find it". The result is shown to you at the end.
Keyboard: arrow keys to aim, Enter to tap, Space if you can't see anything.
See the measurement details
Threshold measured for each color
| Color | Cones | Measured threshold | Typical range | Reading |
|---|
How it went
How it works
Each chameleon differs from the stained glass in only one type of cone: L (red), M (green) or S (blue). For an eye that lacks that type of cone, the patch simply doesn't exist, even when squinting. The pieces of the stained glass also change brightness at random, so you can't find the chameleon by its lightness.
The threshold is the contrast at which you find the chameleon one time out of two, as a percentage of cone excitation. The test picks each screen based on your previous answers and stops as soon as the measurement is precise enough.
Limits
Your screen isn't calibrated: the thresholds are approximate and the typical ranges will be refined using the shared results. The test picks up marked forms well, and the exact type of mild forms less well. Only an exam with an orthoptist or an ophthalmologist gives a diagnosis.
This test is indicative and depends on your screen settings. It does not replace an exam with an orthoptist or an ophthalmologist.