Astigmatism

Astigmatism is probably the most misunderstood vision problem.

Like nearsightedness and farsightedness, astigmatism is a refractive error, meaning it is not an eye disease or eye health problem; it's simply a problem with how the eye focuses light.

In an eye with astigmatism, light fails to come to a single focus on the retina to produce clear vision. Instead, multiple focus points occur, either in front of the retina or behind it (or both).