Astigmatism is an increasingly common refractive problem that usually begins in childhood and may worsen with age as the eye grows and cornea continues to change shape.
Astigmatism relates to the shape of the cornea, which ideally should be spherical n shape, but many people have irregularly shaped cornea, which can cause vision problems.
With astigmatism, the cornea is often oval in shape. The focusing ability of the cornea is compromised because of its irregular shape which contributes to multiple focal points rather than just one focal point on the retina at the back of the eye.
What causes astigmatism?
The cornea is ideally spherical or round in shape. There are two meridians in the eye – one vertical line and one horizontal line cutting through the midway point, (think of the eye like the face of the clock and the 12-6 meridian is one meridian and the 9-3 meridian is the other).
In cases of astigmatism, one meridian is more curved than the other. If you hear the term ‘principal meridians’ mentioned in your particular case, it refers to the steepest and flattest meridians of your eye.
Types of astigmatism
There are three types of astigmatism:
1. Myopic astigmatism: Short-sightedness affects one or both meridians.
2. Hyperopic astigmatism: Long-sightedness affects one or both meridians.
3. Mixed astigmatism: One meridian is short-sighted while the other is long-sighted.
Do I have any other options besides glasses or contact lenses?
If you are craving life without cumbersome glasses and uncomfortable contact lenses, then laser eye surgery is a very real solution that can be used to correct astigmatism, as the procedure allows for the permanent reshaping of the cornea. This means that light entering the eye is focused on the retina at the back of the eye, rather than converging into multiple focal points as is the case with astigmatism.