If not diagnosed until the pre-teen, teen or adult years, treatment takes longer and is often less effective. Astigmatism is a vision condition that occurs when the front surface of your eye, the cornea, is slightly irregular in shape. This irregular shape prevents light from focusing properly on the back of your eye, the retina. As a result, your vision may be blurred at all distances. People with severe astigmatism will usually have blurred or distorted vision, while those with mild astigmatism may experience headaches, eyestrain, fatigue or blurred vision at certain distances.
Most people have some degree of astigmatism.
A comprehensive optometric examination will include testing to diagnose astigmatism and determine the degree. Corneal modification is also a treatment option for some patients. Poor eye muscle control usually causes crossed-eyes. This misalignment often first appears before age 21 months but may develop as late as age six. This is one reason why the American Optometric Association recommends a comprehensive optometric examination before six months and again at age three.