What is Astigmatism?
Medikoe Health Expert
Koramangala, bengaluru, karnataka, india, Bengaluru Feb 9, 2017
Astigmatism is a common vision disorder that causes blurred vision. It happens when the cornea or the clear front cover of the eye is unevenly shaped or sometimes because of the arch of the lens inside the eye.
An unevenly shaped cornea or lens blocks light from focusing correctly on the retina, the light-sensitive exterior at the back of the eye. As an outcome, vision becomes blurry at any interval of space. This can lead to eye irritation and headaches.
Most individuals have some level of astigmatism. Slight astigmatism generally doesn't affect vision or need treatment.
Astigmatism often occurs with other vision disorders like myopia or nearsightedness and hyperopia or farsightedness. Along with these vision problems are mentioned to as refractive errors because they affect how the eyes flex or "refract" light.
The distinct cause of astigmatism is unknown. It can be hereditary and is generally present from birth. It can increase or decrease over time.
A complete optometric inspection will include testing for astigmatism. If required, your optometrist can provide eyeglasses or contact lenses that correct the astigmatism by adjusting the way light enters the eyes.
One more alternative for treating astigmatism is a corneal procedure called orthokeratology (ortho-k). In this noninvasivepainless, procedure, the patient wears a sequence of specially designed rigid contact lenses to slowly reshape the curvature of the cornea.
Some types of astigmatism can be treated with Laser surgery. The laser alters the shape of the cornea by discarding a small amount of eye tissue.
What causes astigmatism?
The arch of the cornea and lens flexes the light entering the eye in order to focus it exactly on the retina at the back of the eye. In astigmatism, the exterior of the cornea or lens has a somewhat different curvature.
The surface of the cornea is shaped more like a football instead of round like a basketball; the eye is ineffectual to focus light rays to a single point. At any distance vision becomes out of focus.
In addition, the curvature of the lens inside the eye can change, resulting in a decrease or an increase in astigmatism. This change often occurs in adulthood and can forego the development of naturally appearing cataracts.
Sometimes astigmatism may evolve following an eye injury or eye surgery.
Astigmatism also occurs due to a relatively unusual disorder called keratoconus in which the cornea becomes progressively thinner and cone-shaped. These results in a great amount of astigmatism, which causes defective vision that, cannot be clearly corrected with eyeglasses. Individuals with keratoconus generally need contact lenses for clear vision and finally may need a corneal transplant.
How is astigmatism diagnosed?
An optometrist can detect astigmatism through a thorough eye examination. Testing for astigmatism evaluates how the eyes focus light and decides the power of any optical lenses required to improve vision. This examination may involve:
With the data from these tests, your optometrist can decide if you have astigmatism. Your specialist will use these results, together with those of other tests conducted, to detect the power of any lens correction you need to issue clear, pleasant vision. Once testing is done, your doctor can talk about the treatment options.
How is astigmatism treated?
People with astigmatism have various options to retrieve clear vision. They involve:
Usually, a single-vision lens is advised to provide clear vision at all distances. However, patients over age forty who have presbyopia may require a bifocal or progressive addition lens.
Laser and other refractive surgery methods
If you have astigmatism, you have a vast range of options to correct your vision disorder. In consultation with your optometrist, you can choose the treatment that best meets your visual and lifestyle needs.