Astigmatism
Astigmatism is a type of short-sightedness that affects the clarity of vision in either the horizontal or vertical plane.
The front surface of eye which works like the first lens in a camera system is meant to be spherical in a ‘perfect” eye. It is very rarely that way. Most people (on a guess 90%) have some degree of asymmetry so it is NOT something to be worried about. It happens because the cornea is shaped more like a rugby ball instead of being round. This makes the eye unable to focus light rays to a single point.
Keratoconus is a relatively rare condition in which the cornea becomes progressively thinner and cone-shaped with resulting high astigmatism. The vision becomes distorted and cannot be corrected with glasses. For these people, contact lenses become the only vision correction option.
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