Astigmatism is usually a stable condition. Astigmatism can be corrected with glasses, contact lenses or surgery. Sometimes astigmatism can be caused by other medical conditions, particularly problems of inflammation of the eyelids. Astigmatism that gets steadily worse over time may in fact be a condition called keratoconus. In keratoconus the cornea gets progressively thinner in one area and begins to bulge. These conditions may require more frequent doctor visits and treatment.