In the astigmatic eye the front of the cornea is not equally curved; it is slightly oval in shape. As a result, the rays of light that enter the eye are bent unequally and cause distortion of the image. Many people have some degree of astigmatism. You can check your existing spectacles by holding them away from your eyes. Then look at some distant object with a straight surface through one of the lenses. Rotate the lens. If you can clearly see the distortion of the straight surface as you rotate the lens you are likely to have lenses for the correction of astigmatism
