Well, in a perfectly-shaped eye, the cornea, or surface layer, is a sphere, like a baseball. It allows light to enter your eyes at the right angle and focus just so on the retina. That means your vision is sharp and crisp. But with astigmatism, the cornea's shape is more like a football than a baseball. This irregularity makes the light rays focus on two points on the retina, not one. This causes blurry, distorted vision.