Myopia is a vision defect commonly known as nearsightedness. Those with this condition can see clearly up to a certain distance, then objects begin to appear fuzzy or out of focus. Distant road signs or chalkboards are often too blurry to read, which can lead to serious problems if their vision is left uncorrected. Most cases of myopia are diagnosed through vision tests administered during childhood years. Even toddlers have been known to demonstrate early symptoms.
If one thinks of the eyeball as a camera, then the retina would be the unexposed film positioned in the back. In a normal eye, light enters through the iris, bringing with it a reflected image. The cornea and lens focus this image squarely on the surface of the retina, albeit upside-down. The optic nerve sends this focused image to the visual area of the brain, where it is translated into a recognizable mental picture.
For people with myopia, however, this process does not work precisely. Because a myopic person's eyeball is slightly longer from front to back, the cornea and lens focus the image in front of the retina. This is not especially noticeable at short distances, but distant images are distorted before they hit the retina.The visual area of the brain can only process what it receives, so the unfocused images cannot be sharpened. The result is blurriness and a lack of visual detail.
Treatment for this condition may include eye strengthening exercises, glasses, contact lenses or laser correction. Some practitioners of homeopathic or alternative treatments believe that myopia is not inherited, but rather a result of overwork and environmental conditions. They recommend a regimen of eye exercises and non-corrective lenses containing a number of pinholes to control the incoming light. Looking through a pinhole can indeed sharpen the focus of many myopic people, although the effect is limited and potentially dangerous.
Most eye doctors prefer the use of prescription lenses, whether it is in the form of eyeglasses or contact lenses. Since myopia is the result of a focus problem, the solution is to change the focal point in the eyeball itself. Refractive lenses or contacts work by allowing the incoming images to fall directly on the retina. There are also contact lenses available which actually reshape the cornea overnight, allowing wearers to see normally throughout the day without aid.
In recent years, laser-based corrective surgery has become a popular option for nearsighted people. A trained eye doctor will anesthetize the patient's eyes and use a laser to remove excess corneal material. The flattened eyeball should be shortened enough to allow normal focus to occur. Long term effects of this type of surgery are still unknown, but most people who undergo the procedure report improved vision without the need for corrective lenses.