Understanding Vision Problems
If Your Eyes Are Normal
Your eyes see objects as light. The cornea focuses light rays onto the retina (a layer that lines the back of the eye). If your eyes are normal, this process produces a focused image on the retina. This makes objects look clear.
If You’re Nearsighted
The cornea and the retina are too far apart if you’re nearsighted. Sometimes, the cornea is also too curved. This makes light rays from distant objects focus in front of the retina. These objects then look blurry.
If You’re Farsighted
The cornea and the retina are too close together if you’re farsighted. Sometimes, the cornea is also too flat. This makes light rays from close objects focus behind the retina. These objects then look blurry.
If You’re Astigmatic
If the curve of the cornea is uneven, light rays cannot focus on just one point on the retina. Instead, they focus on two or more points, either in front of or behind the retina. This makes close and distant objects look blurry.