01Wear your usual glasses or contacts if you use them to read a screen.
02Sit about 18 inches from the screen in a softly lit room. Set your screen brightness to at least mid-level — a dim screen makes the patterns look fainter than they really are.
03Make sure no lamp, window, or overhead light is shining into your eyes or onto your screen — glare can skew your results.
04This test is meant for a generally healthy eye. If you have cataracts, glaucoma, macular degeneration, or very blurry vision that isn't corrected to roughly 20/50, your results may not be reliable.
05You'll test one eye at a time, covering the other.
06For each pattern, choose whether the bars run up, left, or right. The test takes about 3–5 minutes.
07Prefer the keyboard? Tap ← ↑ → to answer and u for unsure.