2. Definition
If you are nearsighted, objects in the distance appear
blurry and out of focus.
Most nearsightedness is caused by a natural change in
the shape of the eyeball. Less often, nearsightedness
may be caused by a change in the cornea or the lens.
The change in shape causes light rays that enter the
eye to focus in front of the retina rather than directly
on it, which leads to blurred vision.
3. Symptoms
In low myopia, the only symptom is indistinct distant
vision. In high myopia, in addition to distance
problems, there is also a problem for near work, simply
because the object has to be held very close to the
eye, which causes a strain on the convergence
mechanism of the eye
4. Causes
The exact cause of nearsightedness is unknown, but
two factors may be primarily responsible for its
development:
heredity
visual stress
There is significant evidence that many people inherit
nearsightedness, or at least the tendency to develop
nearsightedness. If one or both parents are
nearsighted, there is an increased chance their
children will be nearsighted.
5. Treatment
treating nearsightedness has to do with orthokeratology , also known
as corneal refractive therapy. It is a non-surgical procedure that
involves wearing a series of specially designed rigid contact lenses to
gradually reshape the curvature of your cornea. The lenses place
pressure on the cornea to flatten it. This changes how light entering the
eye is focused.
6. Prevalence
Nearsightedness is a very common vision condition
affecting nearly 30 percent of the U.S. population.
Some research supports the theory that
nearsightedness is hereditary.
Generally, nearsightedness first occurs in school-age
children. Because the eye continues to grow during
childhood, it typically progresses until about age 20.
