Astigmatism is a vision problem cause by by an irregularly shaped cornea or lens.http://www.bbc.co.uk/health/physical_health/conditions/astigmatism2.shtml With astigmatism, there is more than one focal point on the retina.http://www.webmd.com/eye-health/understanding-astigmatism-basics Most people have a degree of astigmatism, however slight or severe. It is not normal for the cornea to develop into a perfect spherical shape.http://www.bbc.co.uk/health/physical_health/conditions/astigmatism2.shtml Astigmatism can cause blurry or distorted vision.http://www.webmd.com/eye-health/understanding-astigmatism-basics
The cause of astigmatism is unknown. Some of the possible causes are genetics, the weight of an eyelid on an eyeball, scarring on the cornea after it has healed from injury or infection, or a change to the shape of the cornea after injury or surgery. http://www.webmd.com/eye-health/understanding-astigmatism-basics
Symptoms
People who have minor astigmatism do not experience any major symptoms. The curvature of the cornea is not significant enough to cause any vision problems and blinking can help the cornea preserve a spherical shape. People with major astigmatism experience noticeable vision problems such as distorted or blurred vision.
Diagnosis
An optometrist or ophthalmologist will examine the eyes to determine if an individual has astigmatism. Astigmatism may be diagnosed with another condition such as with nearsightedness and farsightedness.http://www.webmd.com/eye-health/astigmatism-eyes Some tools used to find and measure astigmatism are
- Keratometer: Measures the amount of light that reflects off the surface of the cornea.http://www.mayoclinic.com/health/astigmatism/DS00230/DSECTION=tests-and-diagnosis
- Keratoscope: Projects light in the shape of rings on the cornea. The keratoscope measures the reflection of light on the cornea and the degree of the astigmatism.http://www.mayoclinic.com/health/astigmatism/DS00230/DSECTION=tests-and-diagnosis
- Videokeratoscope: Measures the curvature of the surface on the cornea.http://www.mayoclinic.com/health/astigmatism/DS00230/DSECTION=tests-and-diagnosis
Treatment
- Eye glasseshttp://www.mayoclinic.com/health/astigmatism/DS00230/DSECTION=treatments-and-drugs
- Toric contact lenseshttp://www.webmd.com/eye-health/astigmatism-eyes
- LASIK eye surgeryhttp://www.mayoclinic.com/health/astigmatism/DS00230/DSECTION=treatments-and-drugs
- Photorefractive keratectomy surgeryhttp://www.mayoclinic.com/health/astigmatism/DS00230/DSECTION=treatments-and-drugs
A Health Byte: Astigmatism
The following video discusses what astigmatism is, how it is diagnosed, and how to treat it. Astigmatism causes blurred vision because of the shape of the cornea or the irregular shape to the lens. When light goes into the eye with an abnormally shaped cornea or lens, the eye will not be able to focus properly causing a blurred vision, either near or far. Most people have some degree of astigmatism, ranging from slight to severe. Doctors will check for vision, a refraction test to determine prescription lenses for nearsightedness and farsightedness, and measure the curvature of the cornea. Treatments are glasses, toric contact lenses, and surgery.
Disclaimer
The content in this page is not a substitute for professional medical advice. Please contact a doctor before using the information presented here.
References
Fast Facts
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First identified
Thomas Young in 1801
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Common symptoms
Headache, fatigue, eyestrain, blurred vision
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Causes
Weight of eyelid, corneal scarring, eye injury
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Risk factors
Family history
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Prevention
No known preventive measures
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Diagnosis
Eye exam
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Available treatment and prognosis
Glasses, toric contact lenses, surgery
