There are three main types of astigmatism
Myopic:- This is a situation where one or both principal meridians are near sighted.
Hyperopic:- This is a situation where one or both the meridians are farsighted.
Mixed:- This happens when one of the principal meridians is farsighted and the other is nearsighted.
Most of the times astigmatism occurs early in life, so early eye examinations are very important in order to treat such vision problems.
What are the causes of Astigmatism?
The exact cause of Astigmatism is not yet clear, however genetics can be considered as one of the main factor. Often it may be present at birth but start to develop later in life. An eye surgery or any injury to the eye can result is Astigmatism.
What are the different symptoms of Astigmatism?
The symptoms of Astigmatism might not be the same for everyone. It differs from person to person. Some people might not have any symptoms at all.
Following are some of the symptoms of Astigmatism.
Strain in eyes
Difficulty seeing at night.
Fuzzy, blurry and distorted vision
Who can get Astigmatism?
It can occur in both children and adults. However you are more likely to get astigmatism if you have any of the following.
If you have a family history of astigmatism or any disorders related to eyes.
Thinning or scarring of your cornea.
If you have excessive nearsightedness, where you cannot see objects that is far away.
If you have excessive farsightedness, where you cannot see objects that is close to you.
If you have under gone an Eye surgery such as cataract surgery.
How is Astigmatism Diagnosed?
Routine eye exam helps to detect astigmatism. An optometrist may use several tests to diagnose Astigmatism.
Refraction Test: This test is done with the help of optical refractor. It is a machine with multiple corrective glass lenses of different strengths. You will be asked to read a chart while looking through these lenses. This will help your doctor to find the exact lens that corrects your vision.
Keratometry: This test is used to measure the curvature of your cornea with the help of instrument known as keratometer.
Visual Acuity Assessment Test: During this test you will be asked to read letters from a chart which is at specific distance. This will help your doctor to know how well you can see the letters.
Below are some of the test which is used to diagnose Astigmatism:
What are the different Treatments for Astigmatism?
Corrective Lenses- Astigmatism can be treated by corrective lenses. It is one of the most common treatment for astigmatism
Below are the two types of corrective lenses:
Eyeglasses: Eye glasses are made up of special lenses which help to correct the uneven shape of an eye, apart from astigmatism it can also correct other refractive errors
Contact lenses: Astigmatism can be also be corrected by contact lenses. There are variety of contact lenses for e.g. - hard, soft, disposable, rigid, bifocal etc. You must consult your doctor before choosing the contact lenses in order to know which contact lens is best for you.
Contact lenses are also used in orthokeratology treatment where you have to wear rigid contact lenses for limited period of time in order to correct the irregular curvature of your eyes. However once you stop this treatment your eye will return to its previous shape.
Using contact lenses for a long period of time can lead to infection in the eye.
Refractive Surgery: In severe cases your doctor may suggest Refractive surgery. This surgery helps to correct the problem by reshaping the eye surface.
Following are the methods of refractive surgery:
Lasik surgery: (Laser-assisted in-situ keratomileusis)There are many types of surgeries to correct your vision and Lasik eye surgery is one among them, this can prove beneficial for the people suffering from astigmatism, farsightedness, nearsightedness etc.
This surgery helps to reshape the front part of an eye which is known as cornea, The surgeon makes a thin circular cut into the cornea with the help of an instrument known as keratome or with a special cutting laser, and then the flap is lifted in order to shape the cornea under the flap this is done with the help of excimer laser. An excimer laser does not produce heat like other lasers.
Lasek surgery- (Laser-assisted subepithelial keratomileusis) it is better to go for LASEK surgery if you have a thin cornea or you are at a high risk of having an eye injury at your work place. In this surgery the surgeon folds back the much thinner layer of cornea which protects your eyes or makes it less vulnerable to damage
Photorefractive keratectomy (PRK) In this treatment the outer protective layer of the cornea is removed before using an excimer laser to shape the cornea.