Short-sightedness or myopia is a sight problem that affects your ability to see objects in the distance.  People who are short sighted often see near objects clearly, but distant objects appear blurred.  Myopia is a problem with the eyes ability to focus light through your eye, if you are short sighted the image is formed before reaching the retina.  Generally short sightedness occurs when the eye grows too much and becomes too long from the front to the back, some cases can run in families.  Short sight can be corrected with glasses or contact lenses.