Vision is distorted when the surface of the cornea lens has an uneven curvature; sometimes, it is the eye’s lens that is irregularly shaped. This type of irregularity causes light to focus on more than one spot in the back of the eye, resulting in blurred vision.
How the Eye Works
The eye’s surface, or the cornea, is convex. A well-shaped cornea allows light rays that hit it to bend through the pupil, pass through the lens, and focus precisely on the retina at the back of the eye. The retina converts the light rays into electrical impulses that are sent through the optic nerve to the brain, where a clear image is produced.