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Available Treatments at Siesper Laser Eyecare
LASIK Cataract
Care Glaucoma
Care INTACS Reconstructive
Eye Surgery
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Eye Care Information
Philadelphia, Pennsylvania
It is estimated that over
half the world's population experiences common vision
problems such as nearsightedness (myopia), farsightedness
(hyperopia) and astigmatism.
Imagine getting up in the morning and seeing the alarm
clock without pulling it to your nose or putting on
your glasses. Imagine getting dressed or going to bed
without the bathroom rituals of putting in or taking
out your contact lenses. Imagine how your view of the
world would change and how the world would view you
without glasses or contacts. |
(“normal” vision)
(nearsightedness)
(farsightedness)
(“ghost” vision)
(reduced focus-adjusting
ability)
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Anatomy of the Eye
Much like a camera, the eye works by focusing
light rays. Light entering the eye first passes through a
transparent layer called the cornea. The cornea acts as a
lens. Behind the cornea, another lens--the crystalline lens--further
focuses the light before it reaches the retina at the back
of the eye.
Just as a camera does not produce clear photos if the incoming
light is poorly focused, so will the eye produce unclear images
if light is not correctly focused on the retina.
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Emmetropia (“normal”
vision).
What is referred to as “normal” vision,
or emmetropia, happens when light rays focus precisely on
the retina
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Myopia (nearsightedness).
Nearsighted people see near objects better than those farther
away. Nearsightedness, or myopia, happens when light rays
from distant objects come to focus too quickly (in front of
the retina instead of on it). This is because the eyeball
is too long or steep for the focusing system of the eye. For
light rays to focus precisely on the retina, the cornea usually
needs to be flatter.
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Hyperopia (farsightedness).
Farsighted people see far away objects better
than those that are near. Farsightedness, or hyperopia, occurs
when light rays from distant objects come to focus too late
(behind the retina instead of on it). This happens because
the eyeball is too small, short or flat for the focusing system
of the eye. For light rays to focus precisely on the retina,
the cornea usually needs to be steeper.
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Astigmatism (“ghost”
vision).
Astigmatic people see with double or “ghost” vision.
Both far and near objects appear out of focus. This is because
of the uneven diameter of the cornea. (Oblong-shaped, for
instance.) For light rays to focus precisely on the retina,
the cornea usually needs to be more evenly round.
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Presbyopia (reduced focus-adjusting
ability).
Presbyopic people have a reduced focus-adjusting ability.
This results from a loss of elasticity in the eye's lens,
often as part of the aging process.
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