Astigmatism is a medical condition that affects the vision and causes blurred vision. In most of the cases, astigmatism results due to the irregular shape of the cornea, or because of the abnormal curvature of the lens inside the eye. The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens inside the eye, cornea refracts the light and it is responsible for about two-thirds of the eye's total optical power. People are usually born with the conditions for astigmatism, and this imperfection may also occur in combination with nearsightedness or farsightedness. It is a very common condition, and most of the people have it more or less pronounced. In most of the cases, it doesn’t require any kind of treatment. However, in some people astigmatism causes visual disturbances, eye discomfort and headaches and demands a corrective action.
Causes of astigmatism
As previously mentioned, the cornea and the lens are responsible for focusing images. The curvature of these elements should be perfectly smooth in order to get perfectly smooth image when the incoming light gets through them. Astigmatism occurs when the curvature inside the eye has slightly different shape in one direction from the other. The surface of the cornea or lenses may somewhere appear rather flatter or steeper than smooth, causing the improper refraction of light rays and resulting in blurred vision. Blurred vision may occur in every direction, either horizontally, vertically or diagonally, depending on the location of distortions.
Symptoms of astigmatism
The most common symptoms of astigmatism include distortion in parts of patient’s visual field, blurred vision, eyestrain, headaches, squinting, asthenopia and fatigue. Mild astigmatism is usually asymptomatic and doesn’t require any kind of medical attention. However, if the quality of vision affects one's activities and the ability to perform daily tasks, one should see an eye doctor. Eye doctor will conduct a regular eye checkup to determine the degree and type of astigmatism and decide about the corrective measures. Regular eye checkups are recommended for all people older than 40. The examinations should be scheduled to every two to four years until the age of 65. After the age of 65, patients should check their eyes annually, especially if they are already diagnosed with astigmatism.
Treatment for astigmatism
Treatment for astigmatism is aimed to correct the curvature that is causing blurred vision. Most commonly the treatment will involve wearing corrective lenses or eyeglasses. In some cases, doctors may suggest refractive surgery to correct the problem by reshaping the surface of the eye. Refractive surgeries include LASIK surgery, photorefractive keratectomy, and laser-assisted sub epithelial keratomileusis.