Astigmatism is a common condition that causes blurry vision.  This occurs because the front part of the eye called the cornea is shaped irregularly like a football vs. round like a basketball.  This irregular shape prevents light to be focused on the proper section of the retina or back of the eye.  As a result, vision is often blurred and headaches, eyestrain or fatigue can occur.  Astigmatism is usually corrected with glasses, contact lenses or refractive surgery.