What causes astigmatism?

What causes astigmatism?

Astigmatism is often hereditary, which means it’s passed down from your parents. It can also be the result of eyelids putting pressure on the cornea. It can get better or worse over time.

Sometimes, astigmatism happens after an eye injury or surgery. Another cause is a condition called keratoconus. In this condition, the cornea becomes thinner and more cone-shaped over time. You end up with severe astigmatism. Some people with keratoconus need a corneal transplant.