Nearsightedness (myopia) is a common cause of blurred vision. It
can be mild, moderate, or severe. If you are nearsighted,
objects in the distance appear blurry and out of focus. You
might squint or frown when trying to see distant objects
clearly. View a photo as seen through a normal and a nearsighted
eye. Nearsightedness is usually a variation from normal, not a
disease. Less often, nearsightedness happens because of another
disease or condition. is caused by a natural change in the shape
of the eyeball. Less often, nearsightedness may be caused by a
change in the cornea or the lens. These problems cause light
rays entering the eye to focus in front of the retina. Normally,
light focuses directly on the retina. See a picture of the parts
of the eye. There is nothing you can do to prevent
nearsightedness. The main symptom is blurred vision when looking
at distant objects. You may have trouble clearly seeing images
or words on a blackboard, movie screen, or television. This can
lead to poor school, athletic,