a- entry 2 + Greek stigmat-, stígma "mathematical point, mark, tattoo mark" (more usually stigmḗ in this sense; referring to the point on the retina at which light rays converge in a normal eye) + -ism — more at stigma Note: The term astigmatism was introduced by the British...
The meaning of ASTIGMATISM is a defect of an optical system (such as a lens) causing rays from a point to fail to meet in a focal point resulting in a blurred and imperfect image.
astigmatism(əstĭgˈmətĭzˌəm), type of faulty vision caused by a nonuniform curvature in the refractive surfaces—usually the cornea, less frequently the lens—of the eye. As a result, light rays do not all come to a single focal point on the retina. Instead, some focus...
astigmatism meaning, definition, what is astigmatism: difficulty in seeing clearly that is cau...: Learn more.
Astigmatism is a vision problem that results due to abnormal curvature of the eye's cornea or lens. In order to see clearly, the eye must be able to focus light into a single plane onto the back of the eye at the retina. The word astigmatismcomes from the Greek "a" meaning "without...
Astigmatism is fairly easy for an eye doctor to fix with glasses, contacts, or surgery. Astigmatism Symptoms Symptoms of astigmatismmay include: Blurry or distorted vision Eyestrain Headaches Trouble seeing at night Is astigmatism genetic? Experts think the condition is genetic, meaning if you have ...
Since the 1990s, middle and high school in more than two dozen states have experimented with later school start times. (78) The results have been encouraging: more sleep, increased attendance, better grades and fewer driving accidents. But most school still start early, meaning teens have their...
The word astigmatismcomes from the Greek "a" meaning "without" and "stigma" meaning "spot." To see clearly, the eye must be able to focus light into a single plane at the surface of the retina. In astigmatism, a point (or spot) of light is focused at two different planes, causing ...
"defect in the structure of the eye whereby the rays of light do not converge to a point… See origin and meaning of astigmatism.
No, not always. Some astigmatism is very mild, and sometimes astigmatism only occurs in one eye while the other eye has clear vision. Prescription eyeglasses for astigmatism are generally considered optional if your uncorrected vision (meaning your vision without corrective lenses) is 20/40 or bet...