What is astigmatism - a visual defect associated with a violation of the shape of the lens, cornea or eye, as a result of which a person loses the ability to clear vision. With spherical optical lenses, the defect is not fully compensated. If astigmatism is not treated, it can lead to amblyopia and a sharp drop in vision. Without correction, astigmatism can cause headaches and pain in the eyes. In a healthy eyeball, the cornea and lens have even spherical shapes. In violation of the natural form of these elements, astigmatism develops - a pathology of vision.