Contrast Sensitivity Test

1. Set your screen brightness to maximum, sit about 50 cm (or an arm’s length) away, and wear your usual glasses.
2. For each letter, choose the matching option or Can’t see it. Each level has up to 3 letters; get 2 right to move on to the next, lighter level.
3. The test stops after 2 incorrect answers at a level. See the lowest contrast you could read and share your result.

Visual acuity and contrast sensitivity aren't the same

A standard eye exam measures visual acuity: how well you can read sharp, black letters that get smaller and smaller. Contrast sensitivity measures something different: how well you can see large but faint objects, like a gray step at dusk or a pedestrian in the fog. That's why someone with 20/20 vision can still have trouble seeing in low light.

This test follows the idea behind letter-based contrast tests: the letters stay the same size and get lighter at each level, from 50% to less than 1% contrast against a white background. The displayed contrast accounts for color rounding on your screen.

This is an informal test: your screen affects the results

Brightness, glare, viewing angle, and monitor calibration can all affect what you see. Use the result for curiosity and comparison on the same device, not for diagnosis. Contrast sensitivity often decreases with age and with conditions like cataracts and glaucoma. If you notice that it's getting harder to see at night or in low light, see an eye doctor.

For color vision, try the color blindness test.