Astigmatism is a vision condition that causes blurred vision due to the irregular shape of the cornea, the clear front cover of the eye, or sometimes the curvature of the lens inside the eye. An irregular shaped cornea or lens prevents light from focusing properly on the retina, the light sensitive surface at the back of the eye. Astigmatism frequently occurs with other vision conditions like nearsightedness (myopia) and farsightedness (hyperopia).
The specific cause of astigmatism is unknown. Astigmatism occurs due to the irregular shape of the cornea or the lens inside the eye. The cornea and lens are primarily responsible for properly focusing light entering your eyes allowing you to see things clearly. Astigmatism can be diagnosed through a comprehensive eye examination. Testing for astigmatism measures how the eyes focus light and determines the power of any optical lenses needed to compensate for reduced vision.
Persons with astigmatism have several options available to regain clear vision. Eyeglasses are the primary choice of correction for persons with astigmatism. Contact lenses can offer better vision than eyeglasses. Orthokeratology (Ortho-K) involves the fitting of a series of rigid contact lenses to reshape the cornea, the front outer cover of the eye. The prevalence rate of astigmatism was 19.2%. This was not different between genders, ethnic groups, or age. The prevalence of astigmatism and myopia was 9.8% in Singapore.