The cornea and lens of the eye work together to properly focus visual images on the retina. If an image is out of focus, it is because the overall shape of the eye is incorrect or because the cornea does not have the proper curvature. When the eye is too big or the cornea is too steep, visual images are focused in front of the retina. This condition is called nearsightedness or myopia.
Myopia normally starts to appear between the ages of eight and twelve years old, and almost always before the age of twenty. Once myopia starts, as the body grows, the myopia often increases. It typically stabilizes in adulthood. Changes in glasses or contact lens prescriptions are necessary during growth periods.
Someone with myopia has an inability to see objects at the distance, such as street signs, chalk boards and television. Many times, myopia is diagnosed during school screenings.
The treatment for nearsightedness includes lenses which allow visual images to be focused on the retina. These lenses can be in the form of contact lenses or glasses. Once the eye has stabilized and myopia is no longer progressing, laser vision correction is an option for many.