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A Science Lesson In How Contacts Correct Vision Problems |
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Contact lenses have become an increasingly popular
alternative to glasses for correction of visual problems. With their
ease of use and their ever-increasing level of comfort, it is easy to
see why so many people have turned to contact lenses to help them see.
In addition, most people find themselves to be more attractive looking
when wearing contact lenses and prefer to wear them while engaging in
sports. But, how exactly do contact lenses help improve site and what
are the differences between the many types available?
The miracle of contact lenses
For those individuals with
visual problems, there is a problem between the length of their eye and
its refractive power. As a result, the eye experiences a refractive
error. A refractive error is a problem in which the eye fails to focus
light properly. As a result, the person has decreased visual acuity, or
the ability to see clearly. The contact lens helps correct this problem
by focusing the light properly onto the retina. As a result, contact
lenses are capable of correcting the vision of those with myopia (near
sightedness), hypermetropia (far sightedness), presbyopia, and
astigmatism.
Contact lenses, which are held in place by the
natural tears created by the eye, form a thin layer over the eye to
assist with refocusing. For those who have myopia, the problem is with
seeing objects at a distance. The contact lenses prescribed to patients
with myopia, therefore, are concave. This helps to properly refocus the
light onto the retina. A patient with hyperopia, on the other hand, has
difficulty seeing objects close up. Therefore, convex contact lenses are
used to help redirect the light in their eyes.
For those with
astigmatism, the problem is a little different. An irregularly shaped
cornea characterizes astigmatism. Therefore, the light entering the eye
is focused on two separate points within the eye. Originally, contact
lenses were unable to assist those with astigmatism at achieving better
vision. New “toric” lenses, however, have been developed to help improve
the vision of those with astigmatism, as well.
Presbyopia, which
is the natural aging of the eye and resulting loss of sight, makes it
difficult for the patient to shift from viewing far objects and near
objects. This condition also makes it difficult for patients to read.
Amazingly, bifocal contact lenses are now available for those with
presbyopia, making it possible for them to be free from wearing glasses,
as well.
Choosing the contact lenses that are right for you
With
so many advancements in contact lens technology, it can be easy for a
person to become confused by the multitude of choices available. Two
forms of contact lenses currently available are daily wear contact
lenses and extended wear contact lenses.
It is important to
remove the contact lenses from your eyes before going to bed. But, with
the coming of age of extended wear contact lenses, it has now become
possible to wear these lenses for six nights in a row. Again another
revolution, there are these continuous wear contact lenses that can be
worn non-stop up to thirty nights in a row. Thecnology has made it
possible as these lenses are highly oxygen permeable which helps to keep
the eye healthy and irritation free.
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