What happens to the eye in astigmatism?

What happens to the eye in astigmatism?

Our eyes have a spherical, or round, shape. When light enters the eye, it refracts evenly. Refraction mean light changes direction when it enters your eye at an angle. When light refracts evenly, it focuses precisely on the retina at the back of your eye. You see objects clearly.

If you have astigmatism, your eye’s shape is like a football or the back of a spoon. When light enters the eye, it refracts unevenly — more in one direction than the other. The light can’t properly focus on the retina. When that happens, only one part of the object is in focus at a time. At any distance, things look blurry and wavy. Some people with astigmatism experience eyestrain rather than blur, while others experience both.

The curvature can change, so astigmatism can increase and decrease over time.