Definition of "astigmatism" []

• A visual defect in which the unequal curvature of one or more refractive surfaces of the eye, usually the cornea, prevents light rays from focusing clearly at one point on the retina, resulting in blurred vision. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "After the surgery, I definitely saw better - my previous vision had been -7 and -7.5 with severe astigmatism, which is a short step away from being totally non-functional - but after two weeks, I went back in for another corrective round."
• "If your eye is squished on one side, called an astigmatism, your lenses should compensate for that."
• "There is an optical condition of the eye known as astigmatism, in which the cornea is usually at fault."