Narsightedness is caused by a refractive error in the eye and this occurs at times when the eye has a surplus of optical power lengthwise from the front to the back. As a result the eye projects the light rays from faraway objects to a mid point of the eye instead of onto the retina. Such images are perceived by the brain as blurry in appearance. When glasses or contact lenses are worn the problem is solved as the light is once again refracted in order to project the image to the place it belongs, on the retina.
In a similar way to which some people have larger hands than others, when the eye is larger or elongated, Myopia occurs. The condition is also considered to be hereditary and children born of two nearsighted parents have a 33% chance of developing the condition. For the most part, myopia tends to show itself in a hereditary way in children aged between 8 and 12 years. As the eyes grow there could well be a period of rapid changes until stabilization is reached in adulthood.
Performing close work may affect an already existing myopia condition but it will not simply appear in someone doing close work that does not already have it. Middle age often sees the onset of myopia and it is recognized as an early symptom of cataracts forming. It can also be an indication of the rare condition of keratoconus which makes the cornea of the eye change shape and become conical as well as a side effect of uncontrolled diabetes.
Whilst there are several other symptoms of nearsightness which may occur such as burning or tired eyes, headaches and a restricted tolerance to reading, these are not indicative of myopia being present as the only true symptom of myopia is the fact that objects in the distance tend to appear fuzzy. It's worth bearing in mind that when a youngster chooses to sit up close to the television, it does not necessarily mean he or she can not see it properly – it's simply a matter of personal choice.
The results of a new study suggest that children who spend more of their time out in the fresh air are less likely to have this condition than the ones who channel their energy into playing video games or looking at a computer or television screen.
Treatment for myopia is reliably straight and the problem can be effectively rectified with glasses or contact lenses. Children's eyes should be tested for any changes on an annual basis and adults need their eyes examined every two or three years if they have no reason to believe their eyes have altered since the last test took place.
These days more and more people are deciding on surgical correction such as using LASIK or PRK. LASIK works by making a flap in the cornea and by taking away a small piece of tissue prior to the flap being reattached. The eye can then focus again normally as the length of the eye from front to back is reduced.
As with any surgery being considered it is important to carry out some research into the possible or likely side effects before going ahead with the treatment.