MYOPIA OR SHORT SIGHTEDNESS
It is a term that means your eyes focus on close objects,
but distant images are blurry. It means that the eye is unable
to focus on distant objects. It occurs when light entering
the eye focuses in front of the retina instead of directly
on it. Nearsightedness is caused by a steeper cornea or a
too long eye relative to the optical power of the eye, or
because the optical power of the eye is too high relative
to the length of the eye.
ASTIGMATISM
Astigmatism is a defect that occurs when some portions of
the cornea is more curved in one direction (oval) than the
other (spherical), so light rays are not focused equally in
all directions, causing imperfect images of indistinctness
of vision.
HYPEROPIA OR LONG SIGHTEDNESS
It occurs when light entering the eye focuses behind the retina,
instead of directly on it, Objects up close cannot be focused
clearly. Upward deviation of the eye is sometimes due to a
paresis of one of the muscles that either elevate of depress
the eye. Farsightedness implies that one eye is deviated upward
relative to the other.
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