Astigmatism is a common vision condition, or refractive error, that often accompanies myopia (nearsightedness) and hyperopia (farsightedness). A refractive error means that the shape of your eye does not refract the light properly, so that the image you see is blurred. Astigmatism occurs when the curvature of the cornea is irregularly shaped, scattering light rays entering the eye so that they are focused both in front of and behind the retina, rather than directly on the retina. Vision is blurred at all distances. For our eyes to be able to see, light rays must be bent or “refracted” so they can focus directly on the retina, the nerve layer that lines the back of the eye. Together the cornea and the lens refract light rays. The retina receives the picture formed by these light rays and sends the image to the brain through the optic nerve.