Short sightedness is also called nearsightedness or Myopia is a common vision problem when the eyes can focus on close objects but distant objects are blurry. Long sightedness, also call far sightedness or Hyperopia is the opposite of Myopia. The eyes can focus on distant objects but not on close objects.
These vision problems are very common, about 30 percent of Americans are nearsighted and 60 percent are farsighted to some degree.
The shortsighted eyeball is too long causing the image focused in front of the retina. The symptoms of nearsightedness are blurred vision but also eye strain and sometimes headache.
The causes of nearsightedness are partly genetic and partly environmental. A person who constantly does close work could end up with Myopia. You can be diagnosed with nearsightedness at any age even after age 40.
The farsighted eyeball is too short causing the image focused behind the retina. Again the result is blurred image.
Genetic factors play a role at developing long sightedness. If the farsighted eye is not corrected it can get worse. It is possible that one eye nearsighted one eye farsighted.
Myopia and Hyperopia can be combined with other eyesight problems especially with Astigmatism. The causes of Astigmatism are irregular shaped cornea or irregular shaped lens causing an out-of-focus vision.
Narsightedness and farsightedness can be corrected different ways. One solution is eyeglasses. Another solution is contact lenses. Glasses and contact lenses are not going to make your eyes better they just help the eyes to focus on the retina. Eye surgery is another possibility. With eye surgery there are some risks involved.
You can also correct your vision and actually improve your vision with eye exercises. There are nearsighted eye exercises and farsighted eye exercises. Eye exercises can help Astigmatism too.