“My eyes are so bad,” is a common phrase people say around the world. Some of these people have eye diseases and have less vision than normal even when they have their vision is corrected with refractive surgery, contact lenses, or eyeglasses. The other type of people who have “bad eyes” can see normally when they have tier vision corrected with eyeglasses, contact lenses, or refractive surgery.
This second type of “bad eyes” is the result of a refractive error in their eyes. A refractive error is not a disease. The eye is healthy. The eye can be near-sighted, far-sighted, or have astigmatism. This simply means that the light from outside images is not focused onto a single point inside the eye. How light is focused inside the eye depends on the size and shape of the eye.
Since humans are all different sizes and shapes, human eyes are also different sizes and shapes. If the shape and size of a healthy eye enables you to focus the light inside the eye to a single point, you can see 20/20. You will see less than 20/20 if you have a different size and shape of your eye. However, the light can be refocused with eyeglasses, contact lenses, and refractive surgery to bring it to a single focus. So, people who wear glasses often have healthy eyes and just need the direction of the light correctly focused. Eyes may be called “bad”, but usually they just need some help and attention.