Your cornea is the clear, round dome that covers the eye’s iris and pupil. When there’s an imperfection in the curvature of your cornea, it’s called a corneal astigmatism. When the shape of your eye’s lens is distorted, it’s called a lenticular astigmatism.

Ideally, the cornea and lens are both smooth and curved symmetrically in all directions, which helps your eye focus, or refract, light rays sharply. But with either type of astigmatism, light rays are not refracted properly, so your vision for both near and far objects appears blurry or distorted. Objects may be blurry or appear to be taller, wider or thinner than they actually are.

Astigmatisms are common, but they’re also one of the most misunderstood refractive disorders. In addition to blurred or distorted vision, astigmatism can cause eye strain and headaches after prolonged periods of visual stimulation, such as from reading a book, looking at electronic screens, or watching a movie. (more…)