How Faint a Pattern Can You Spot?
Contrast sensitivity is how faint a pattern you can detect. This 60-second demo uses Gabor patches, a standard stimulus in vision science, to let you try a contrast task. It's practice, not an eye exam.
How It Works
You'll see 2 circles. One contains a faint striped pattern.
Click the one with the pattern. The pattern gets fainter each round.
After 20 rounds, you'll see the faintest pattern you found on this screen.
💡 Tip: Sit about arm's length from your screen. Zoom your browser to 100%. Reduce screen glare.
What Is Contrast Sensitivity?
More Than Just Visual Acuity
Visual acuity, what the familiar letter chart checks, describes your ability to resolve small, high-contrast details. But real life isn't like an eye chart: much of the visual world is made up of subtle contrast differences.
Contrast sensitivity describes how well your visual system detects differences in luminance between adjacent areas. It plays a part in reading in dim light, driving at dusk, recognizing faces, and getting around safely.
Why It Declines With Age
Contrast sensitivity tends to decline with age, through changes in both the optics of the eye (lens yellowing, smaller pupils) and neural processing in the visual cortex.
Some causes, such as cataract, are treatable, so a noticeable change deserves an eye exam. Perceptual-learning research has found that adults get better at detecting faint patterns they practice, such as Gabor patches; how much that carries over to everyday vision varies by study.
The Contrast Sensitivity Function (CSF)
Vision scientists describe contrast sensitivity as a function of spatial frequency — how fine or coarse the pattern is. Your CSF forms an inverted-U curve: you're most sensitive to medium spatial frequencies (~3–5 cycles/degree) and less sensitive to very fine or very coarse patterns.
This demo uses one medium spatial frequency, so it shows only one point on that curve. A clinical assessment tests many frequencies; this isn't a screening tool.