Myopia is a condition where near objects are seen more clearly than objects which are far away. The image is focused in front of the retina (back of the eye), rather than directly on it. This can be caused by a cornea that is steeper, or an eye ball that is longer than a normal eye. The main symptom is blurry vision when looking into the distance.
Myopia tends to first develop during adolescence as the eye grows to full adult size. Myopia occurs either due to hereditary factors or due to environmental stress and a subsequent spasm of the eye focussing muscles.
Myopia is corrected with either contact lenses or spectacles. Since these lenses are thickest at the edge, new lens technologies have been developed to produce thinner and lighter lenses.