Myopia is better known as nearsightedness and affects over twenty-five percent of the population. People with myopia are able to see near objects clearly but struggle to see distant objects. Myopia is generally caused when the eyeball is slightly too long, causing the retina to incorrectly perceive light from distant objects. Light still reaches the cones and rods but does so improperly, causing objects in the distance to become blurred and out of focus.
Myopia can also be caused when the cornea is curved or bulged, causing light waves to become distorted. The refraction that results mimics the effects of an elongated eyeball, causing the same symptoms.
People who experience myopia are generally diagnosed in late childhood or early adolescence and in most cases continue to worsen until early adulthood. Myopia is a hereditary disease and, despite urban legend, isn’t caused by reading in dim light or any other form of eye strain. Most people who suffer from myopia can temporarily correct the problem with glasses or corrective contact lenses.
Previous: Common Visual Problems