Astigmatism is a common condition where one or more of the optical surfaces in the eye is not rounded. An eye that has no astigmatism is like a ball and perfectly spherical. An eye with astigmatism is more distorted and shaped more like a football rather than a soccer ball.
This problem can result in vision blur as well as eye strain and trouble changing focus between different distances.
This condition can be fixed by both glasses and contact lenses.