Astigmatism is a common vision condition that happens when a person's cornea is not symmetrical. A normal cornea is round like a baseball. With astigmatism, the cornea curves more severely, like a rugby ball.
What Causes Astigmatism?
Astigmatism can come in combination with short-sightedness and long-sightedness. Because of its asymmetrical curvature, the astigmatic eye focuses light correctly along one axis, but incorrectly along the other. Light entering the eye is not focused on a single point on the retina, so objects both near and far become blurred or distorted producing an effect similar to looking through a pane of wavy glass.
Symptoms of Astigmatism
An eye care professional may diagnose astigmatism through a variety of tests, including a simple vision test, light refraction test, cornea measurement, or electronically mapping the surface of the eye. Common symptoms of astigmatism include:
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Objects both near and far appear blurred
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Inability to read small print
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Constant squinting of the eyes