The cause of astigmatism is unknown. Also, there is no way to prevent it from developing. It may have a genetic predisposition. It’s often present at birth, but it may also develop later in life.
Astigmatism can result from an eye injury, scarring or thinning of your cornea, or previous surgery.
This eye disease is often accompanied by farsightedness (hyperopia) and near-sightedness (myopia), though this isn’t always the case.