Plain English Meaning

Vision problems where the eye can't focus light properly, so things look blurry. Glasses or contacts usually fix it.

Full Definition

Conditions in which the eye does not bend (refract) incoming light correctly onto the retina, producing a blurred image. The most common types are nearsightedness (myopia), farsightedness (hyperopia), astigmatism (uneven curvature of the cornea or lens), and presbyopia (age-related loss of near focus). These disorders are typically corrected with eyeglasses or contact lenses.

Context Anchor

Seen in night vision discussions because small focusing problems can become more noticeable when light is low and visual details are harder to .