What Is Astigmatism?
Astigmatism is a common eye condition that’s easily corrected by
eyeglasses,
contact lenses or surgery.
Astigmatism is characterized by an irregular curvature of the cornea. This
is one type of refractive error. Astigmatism occurs in
nearly everybody to some degree. For significant curvature, treatment is
required.
A person’s eye is naturally spherical in shape. Under normal circumstances,
when light enters the eye, it refracts evenly, creating a clear view of the
object. However, the eye of a person with astigmatism is shaped more like a
football or the back of a spoon. For this person, when light enters the eye it
is refracted more in one direction than the other, allowing only part of the
object to be in focus at one time. Objects at any distance can appear
blurry and
wavy.
What Causes Astigmatism?
Astigmatism can be hereditary and is often present at birth. It can also
result from pressure from the eyelids on the cornea, incorrect posture or an
increased use of the eyes for close work.
What Are the Symptoms of Astigmatism?
People with undetected astigmatism often experience
headaches, fatigue,
eyestrain and blurred vision at all distances. While these symptoms may not
necessarily be the result of astigmatism, you should schedule an eye exam if you
are experiencing one or more symptoms.
How Are Astigmatisms Diagnosed?
Your optometrist or ophthalmologist can diagnose astigmatism with a thorough
eye exam. Astigmatism may occur with other refractive errors such as myopia
(nearsightedness) and hyperopia (farsightedness). Unfortunately, astigmatism
often goes undetected in school-age children.
Because astigmatisms may increase slowly, you should visit your optometrist or ophthalmologist whenever you notice significant changes in your vision. Optometrists are trained specifically to examine the general health of the eyes and prescribe eyeglasses and contact lenses. Ophthalmologists provide total eye care, including exams, diagnosis, and treatment of disease through medication and surgery.
How Are Astigmatisms Treated?
Almost all degrees of astigmatism can be corrected with properly
prescribed eyeglasses or contact lenses. For a person with only a slight degree
of astigmatism, corrective lenses may not be needed at all, as long as other
conditions such as nearsightedness or farsightedness are not present. If the
astigmatism is moderate to high, however, corrective lenses are probably needed.
- Corrective lenses (eyeglasses or contact lenses). For
astigmatism, special corrective lenses called toric lenses are prescribed.
Toric lenses have greater light bending power in one direction than the
other. After performing various tests, your eye doctor will determine the
ideal toric lens prescription for your astigmatism. - Refractive surgery.
Another method for correcting astigmatism is by changing the shape of the
cornea through refractive or laser eye surgery. While there is more than one
type of refractive surgery, specific treatments are recommended on an
individual basis.
Refractive surgeries require healthy eyes that are free from retinal problems, corneal
scars and any eye disease. As technology progresses, it is becoming
more and more important that you explore all options and possibilities before deciding which refractive surgery and
treatment is right for you.
WebMD Medical Reference