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Contact Lenses
Serving the Greater Los Angeles Area
Coming from: Beverly Hills, Santa Monica, Pasadena, Orange County, Ventura County
A corrective contact lens is a contact lens designed to improve vision, whereas
a cosmetic contact lens is a contact lens designed to change the appearance of
the eye. Contact lenses correct vision by refracting or bending light to focus
on the eye's retina. Conditions treatable with contact lenses include nearsightedness
(myopia), farsightedness (hyperopia), and astigmatism.
Heavily tinted contacts change the color of the iris, and are used for
cosmetic reasons. Some standard contact lenses are slightly tinted in order
to make them more visible and, therefore, easier to handle. Cosmetic contact
lenses can also be worn for corrective purposes.
Soft vs. hard contact lenses
Contact lenses may also be classified as either soft or hard. Hard contacts
are typically not disposable, while soft contacts often are. Some soft contacts
are also known as extended wear lenses. The most commonly used contact lenses
today are of the soft variety, invented in 1961. Contact lenses (both soft
and hard) are made of various types of polymers, the latest containing some
variant of silicone hydrogel. Previously, hard contact lenses were made of
a polymer known as PMMA. Rigid gas-permeable (RGP) lenses have replaced them.
Many contact lenses are made of hydrophilic (water-absorbing) materials, thereby
allowing oxygen to reach the cornea, and making the lens more comfortable to
wear.
Toric contact lenses
People with astigmatism, both myopic (nearsighted) and hyperopic (farsighted),
who have been told they are not suitable for regular contact lenses may be
able to use toric lenses. Toric lenses are made from the same materials as
regular contact lenses but have a couple of extra characteristics:
• They have two powers in them, one for spherical correction and the
other for the astigmatism.
•
They are designed to keep the lens in a stable position regardless of eye movement.
Often the lens is weighted more at the bottom and is marked by tiny striations
so the wearer can insert them in the correct position, or they are designed
in such a way that blinking will reset the lens to the correct orientation.
While toric contact lenses can provide patients with a glasses-free lifestyle,
many become bothered by the variability in vision as the lens inadvertently
rotates. Such patients may be excellent candidates for Laser Vision Correction,
which can allow less visual fluctuation than a rotating toric contact lens
allows.
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