Astigmatism is a very common and treatable imperfection in the curvature of the eye that causes blurred distance and near vision. It occurs when either the front surface of the eye (cornea) or the lens inside the eye has mismatched curves. Typically the eye has one curve like a round ball.  Those with an astigmatism the eye has a surface that is egg-shaped. This shape prevents light from focusing properly on the retina and causes blurred vision at all distances.

Astigmatism is often present at birth and may occur in combination with nearsightedness or farsightedness. Often the astigmatism is not pronounced enough to require corrective treatment. When it is, treatment options are corrective lenses or surgery.

Causes & risk factors