The information in this article and on this site is for casual educational purposes, and is not meant to replace the advice of a licensed physician or a Medical Doctor. Use this just as an informal source for finding out what others do. Before trying any of the suggestions, consult with your own physician to get proper treatment.
Nearsightedness: Why do I have it?
You are nearsighted when the eyeball is a little more elongated in the back (Most of the time), and sometimes the lens or the shape of the cornea is the blame.
In most cases, when the eyeball is longer in the back than it should be, the retina is farther back than it should be, so the lens will focus the light rays (or images) slightly more forward than the retina, instead of falling right on it. So the objects you are looking at in a distance will look blurry
The retina is a sensitive membrane that lines the back of the eye, and it is responsible for sending signals to the brain using the optic nerve where these signals are interpreted and an interpretation of it is generates.
Often school age children are diagnosed with eye problems, and mostly with nearsightedness. Yearly checkups make sure that the necessary changes to the glasses are done as the eye is still changing. This usually stabilizes when they reach early to mid 20’s, because their eyesight stabilizes.
Another stage is when people hit their 40’s when the lend becomes a little less flexible so they have to change glasses, and in some cases start wearing reading glasses because the opposite becomes true, they become farsighted and develop Presbyopia which is the difficulty of reading and seeing near objects like reading a book, or focusing on small objects that effects people after they reach their 40’s and 50’s. The solution is to wear reading glasses.