Causes of Myopia
The light rays entering the eye are not clearly focused on the retina instead the image is focused in front of the retina thus making the distant images blurry. This occurs when the cornea is steeper or the eyeball is longer than usual.
It occurs more commonly in those who have a family history of nearsightedness.
It usually appears in childhood and may worsen with age.
Working too much on computers, watching television sitting closely, excessive reading and prolonged close work will result in exertion and more focusing effort and can lead to myopia or worsening of the condition if it already exists.