People with more astigmatism may squint to try to bring objects into focus. Squinting does not hurt your eyes, but it may lead to headaches. Astigmatism can be treated with eyeglasses, contact lenses, or surgery. No one knows for sure what causes uneven corneas. Corneas, like sets of teeth, are rarely perfect.
Astigmatism tends to run in families.
Some people have had irregular corneas since birth. Other people develop astigmatism as they get older when the cornea, like skin and other tissues, loses its flexibility. Astigmatism may develop after cataract or cornea surgery. The main symptom is vision that is never completely clear and sharp at any distance or in any amount of light. Part of your vision may be in focus and part blurry.