What is Astigmatism?

Astigmatism has often been misunderstood to be a form of an eye disease. You can be rest assured that it is NOT a disease. It is simply an eye condition just like Myopia and Hyperopia.


The front part of a non-astigmatic eye looks like a soccer ball, evenly spherical. Hence, when light rays enter the eye, they fall on one part of the eye. In front of the retina for myopic eyes, behind the retina for hyperopic eyes and on the retina for the lucky ones who do not need prescriptive visual correction.

The front part of an astigmatic eye looks like a rugby ball, elongated slightly on one axis. Due to the elongation on one axis, the light rays actually split into two when they pass through the cornea and fall on different parts of the eyes.

They can be classified in the following 3 categories:

  1. Myopic astigmatism – Both light rays fall in front of the retina
  2. Hyperopic astigmatism – Both light rays fall behind the retina
  3. Mixed astigmatism – One light ray falls in front of the retina and the other ray falls behind the retina

What causes Astigmatism?

Astigmatism is a naturally occurring phenomenon which has no pathological implications unless it is related to corneal degenerative diseases like keratoconus. There is no proven theory on the reason why the cornea becomes elongated on one axis.

How to prevent Astigmatism?

Unfortunately, since the cause of astigmatism is still not known, it is not possible to prevent astigmatism.

How to correct Astigmatism?

Astigmatism can easily be corrected with a pair of spectacles or contact lenses. Due to the distorted nature of astigmatic spectacle lenses, it may cause one to have uncomfortable vision. This can be easily avoided with the use of contact lenses. Since contact lenses conform to the shape of the cornea, there is no distortion to the vision. They are also easy to fit and hassle free.

 Stay Healthy & Stay Happy!