Astigmatism is one of several eye conditions known as refractive errors. Refractive errors are those that deal with the angle at which the light enters the eye. This effects the focus of the light on the retina, the nerve that interprets the light into images for the brain.
An astigmatism usually results from an irregular curvature of the cornea, the front surface of the eye. It is not a disease, and is actually a common problem. It can cause a blurring or both distant and nearby objects. This blurred vision can cause headache, fatigue, squinting, and eye discomfort or irritation.
