What is astigmatism?
Astigmatism is a vision condition in which light entering the eye is unable to
be brought to a single focus, resulting in vision being blurred at all distances.
Astigmatism is not a disease, but rather, a vision condition that is quite common.
It often occurs in conjunction with other refractive errors like nearsightedness
and farsightedness.
Why does astigmatism occur?
Typically, astigmatism is caused by the front of your eye (the cornea) being more
oval than round, and not allowing light to focus properly on the back of your
eye (retina). The causes of this irregular shape vary.
In some cases, it may be hereditary or it may result from such factors as pressure
of the eyelids on the cornea, incorrect posture or an increased use of the eyes
for close work.
How common is astigmatism?
 Text blurred by different
focal positions of an astigmatic lens. |
Most people have some degree of astigmatism. However, only individuals with moderate
to highly astigmatic eyes usually need corrective lenses.
What are signs/symptoms of astigmatism?
People with significant amounts of astigmatism will usually have blurred or distorted
vision. Those with mild astigmatism may experience headache eye strain, fatigue
or blurred vision at certain distances.
How is astigmatism diagnosed?
A comprehensive eye examination by your doctor of optometry will include testing
for astigmatism.
How is astigmatism treated?
In general, astigmatism can be optically corrected with properly prescribed and
fitted eyeglasses or contact lenses. In recent years, a number of options to surgically
alter the shape of the cornea, to correct low or moderate astigmatism, have been
developed. These include procedures called radial
keratotomy (RK) and photorefractive
keratectomy (PRK).
Your doctor of optometry can help you decide if these procedures are right for
you. There is also a procedure called orthokeratology which uses a series of rigid
contact lenses to provide improved vision for extended periods of time for people
with astigmatism.
Does astigmatism get progressively worse?
Astigmatism may change slowly. Regular optometric care can, however, help to ensure
that proper vision is maintained.
How will astigmatism affect my lifestyle?
You may have to adjust to wearing eyeglasses or contact lenses if you do not wear
them now. Other than that, astigmatism probably will not significantly affect
your lifestyle at all.
Image credit: en.wikipedia.org/Tallfred. Creative Commons
license BSD.
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