Contrast sensitivity

Faint letters on a light background

1 m
both eyes or one at a time
3 min

1 m

How to take it

01Turn screen brightness all the way up; normal room lighting, no glare.
02Sit 1 meter (about 3 feet) from the screen, wearing glasses if you use them.
03Name the letter on the screen. If you can’t make it out, guess; if you see nothing at all, tap “Can’t see.”
04A level counts if you get 2 of 3 letters right.

Which eye

Look with both eyes open.

An on-screen test is a rough guide, not a diagnosis. Results depend on your screen, lighting and distance; if you have any doubts or your vision gets worse, see an eye doctor.

How to read your result

Normal
- Normal contrast sensitivity≥ 1.65 log
  You can make out very faint letters. On this screen, the result is consistent with normal vision.
Discuss with a specialist
- Contrast sensitivity slightly reduced1.35–1.50 log
  This can happen with age, dry eye, early cataract, or simply because of the screen. If dim light and night driving have become harder, tell your eye doctor.
See an eye doctor
- Reduced contrast sensitivity≤ 1.20 log
  Faint objects are hard to make out. Make sure your screen brightness is at maximum and repeat the test. If the result holds up, you need an eye exam to check the lens, retina and optic nerve.
Today
Skip the tests and see a doctor today
If your vision drops suddenly, you notice a shadow or curtain, flashes of light and a shower of new floaters, straight lines suddenly look wavy, or your eye is painful and red — get help the same day.
When to see a doctor now

Good to know

01 / 04

How the test works

The letters stay large but get fainter and fainter. Visual acuity shows how small you can see; contrast sensitivity shows how faint. When it drops, it explains why things are hard at dusk, in fog and when driving at night.

Other tests

All tests

Contrast sensitivity

How to take it

Good to know

How the test works

What it shows

Normal values

Limitations

Further reading on your results

Other tests

How to take it