Astigmatism
Astigmatism is defined as an irregular curvature in the front portion of the eye, often resulting in blurred vision. This irregular shape prevents light from focusing properly on the back of your eye, the retina. As a result, your vision may be blurred at all distances. Non-uniform shape of the cornea is called corneal astigmatism. A distorted lens shape is a lenticular astigmatism. Both forms are common and can typically be treated with corrective lenses or surgery.
An astigmatism occurs in the eye when outside rays (or beams of light) transmit across two perpendicular planes, yet the focal point for the eye is different for those beams. There are few forms of astigmatism.
Contents
Myopic Astigmatism
A form of astigmatism in which the light rays are brought to a focus in front of the retina.
Hyperopic Astigmatism
Hyperopic astigmatism occurs when one meridian is free of refractive error, but the other is farsighted.
Mixed Astigmatism
Occurs when one principal meridian is myopic and the other hyperopic, thus not perpendicular and creating an irregular shape and vision is often blurry.Also called irregular astigmatism ...read more
Causes
- It can also be the result of pressure from the eyelids on the cornea, incorrect posture, or an increased use of the eyes for close work.
- Astigmatism can be hereditary and is often present at birth.
Symptoms
People with severe astigmatism will usually have blurred or distorted vision,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 is Astigmatism diagnosed?
Astigmatism can only be diagnosed with a thorough eye exam by your optometrist or ophthalmologist. 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 for an eye exam once a year. Optometrists are trained specifically to determine and improve visual acuity with the prescription of eyeglasses or contact lenses. Ophthalmologists can provide total eye care, from examinations and vision correction to the diagnosis and treatment of disease through medication and surgery.
Treatment
Almost all degrees of astigmatism can be corrected with properly prescribed glasses or 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. 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. Another method for correcting astigmatism is by changing the shape of the cornea through 'refractive 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 important that you explore all options and possibilities before deciding which refractive surgery and treatment is right for you.
Some popular toric contact lenses that can help to correct Astigmatism (Independent Consumer Information):
Acuvue Advance for Astigmation
