Myopia or short-sightedness is a refractive error where close objects are seen clearly, whereas faraway objects are seen blurred. This disorder occurs if an eyeball is elongated or the cornea is more bulging than normal standard cur-vature. As a result, the light entering the eye refracts irregularly and the rays refract in front of the retina causing blurred vision of faraway objects.
When Does It Occur?
Short-sightedness is a very frequent eye condition affecting a large number of people. It occurs in childhood and can worsen with years as the body is growing, i.e. until the eye stops growing. Some researches support the theory this condition is hereditary.
Short-sightedness can develop gradually or suddenly, and it often worsens throughout childhood and adolescence. Generally speaking, myopia is prev-alent with school-age children. The eyes continue to grow throughout child-hood; so short-sightedness usually progresses until the age of 20-25.
Causes of Short-sightedness
The basic cause of short-sightedness is an overelongated eyeball. An inter-esting fact is that as the length of the eye increases by 1mm, short-sightedness increases by -3D (diopters). The exact cause of myopia is un-known but experience indicates this condition is hereditary.
If at least one of the parents is short-sighted, there is a higher chance that children will be short-sighted as well.
Night myopia – some people can notice they see faraway objects worse at night. Their pupils dilate too much, which enables more peripheral light to enter the eye, so it cannot focus well.
False myopia – after long work with close objects, the eye may not be able to focus on faraway objects. These are short-term symptoms and vision is re-stored soon. Constant work with close objects can lead to permanent short-sightedness.
Myopia with cataract and diabetes – persons who have the nonregulated diabetic condition can feel changes with their vision at close objects as the level of glucose changes in their blood. Also, some types of cataracts are fol-lowed by the development of myopia.
Treatment of myopia
The options to correct myopia are as follows:
- Spectacles with myopic (-) lenses
- Myopic (-) lenses contact lenses
- Laser intervention
- Implantation of an intraocular lens