astigmatism
Last reviewed 01/2018
Astigmatism is an ametropia caused by differences in curvature in different meridians of the refractive surfaces of the eye so that light rays are not sharply focused on the retina - they in fact result in an elliptical blur on the retina.
Vision may be proportionately blurred both for near and far objects, irrespective of accommodation, and may result in visual fatigue - ocular headaches.
Regular astigmatism can be compensated by spectacle lenses with an appropriately different curvature in two meridians.