Astigmia vs. Astigmatism

astigmatism

(ophthalmology) impaired eyesight resulting usually from irregular conformation of the cornea

(optics) defect in an optical system in which light rays from a single point fail to converge in a single focal point

(optics) A defect of a lens such that light rays coming from a point do not meet at a focal point so that the image is blurred.

(pathology) A disorder of the vision, usually due to a misshapen cornea, such that light does not focus correctly on the retina causing a blurred image.

A defect of the eye or of a lens, in consequence of which the rays derived from one point are not brought to a single focal point, thus causing imperfect images or indistinctness of vision.

(ophthalmology) impaired eyesight resulting usually from irregular conformation of the cornea

(optics) defect in an optical system in which light rays from a single point fail to converge in a single focal point

Astigmatism is a type of refractive error in which the eye does not focus light evenly on the retina, due to a variation in the optical power of the eye for light coming from different directions. This results in distorted or blurred vision at any distance.