Nearsightedness results in the blurring of the vision where distant objects appear out of focus. Nearsightedness is usually not a disease itself but a variation from the normal eyesight and sometimes it can also indicate another serious condition or disease.

Nearsightedness Cause: What Happens in Your Eye?
There is not a single nearsightedness cause. People engaged in work that requires too much eye concentration such as reading or being close to a computer monitor for a prolonged period of time usually gets nearsightedness. This eye disorder is also inherited. So you are most likely to develop myopia if either one or both your parents have this disorder.

In normal eyesight, light rays that enter the eyes will be focused directly on the retina. The retina is a thin nerve membrane in the eye responsible for detecting the light that enters and then signals the brain, along with the optic nerve, (read more ..)