Astigmatism is an eye condition which occurs when the cornea (the front surface of the eye) or the lens has a different surface curvature in one direction from the other eye. A person with astigmatism will see a surface unevenly; there are some areas that are flatter or steeper. Vision is blurred at all distances.
Symptoms of Astigmatism
People with astigmatism will experience the following symptoms:
– distortion, blurriness in some parts of the visual field
Causes of Astigmatism
Astigmatism is a type of refractive error produced when the cornea or lens is not evenly and smoothly curved. Your cornea or lens is steeper in one direction than in another. Astigmatism has two types: lenticular astigmatism (when the lens is distorted) and corneal astigmatism (when the cornea has a distorted shape). The vision may become blurred in more than one direction. It can be vertically, horizontally and diagonally. Astigmatism can combine with other refractive errors such as myopia (nearsightedness) and hyperopia (farsightedness).
Most cases of astigmatism are inborn but some develop after eye injuries, diseases or surgery. Contrary to popular belief, one cannot get astigmatism from reading in poor light or sitting to close to the television screen.
Tests and Diagnosis to determine Astigmatism
Your doctor will probably use a keratometer, which quantifies the amount and orientation of the astigmatism in the cornea by measuring the light reflected from the surface of the cornea. He may also use a keratoscope or a videokeratoscope, which examines the corneal surface curvature and the presence of astigmatism.
Treatment of Astigmatism
Those with astigmatism are first made to wear corrective lenses to counteract the uneven curvature in the cornea. You can wear either contact lenses or eyeglasses. For some cases, doctors will suggest refractive surgery which reshapes the surface of the eye. These surgery methods include LASIK surgery, photorefractive keratectomy and laser-assisted subepithelial keratomileusis.