What is astigmatism?
Astigmatism occurs when the cornea is irregularly shaped. There is another, less common form of astigmatism – lenticular astigmatism, which occurs when the lens is irregularly shaped. Astigmatism causes light rays to converge at two points on the retina instead of just one. Contact lenses can help to correct astigmatism. For more information about, please see here.
A. Astigmatism is a condition that occurs when the cornea has more than one curvature (like a football as opposed to a basketball). These multiple curvatures bend light differently and blurred vision is the result. Light entering the eye focuses on or in front of the retina, multiple focal points.
An astigmatic eye generally has two different meridians, at 90degrees to each other, which cause images to focus in different planes for each meridian. The meridians can each be either myopic, hyperopic or emmetropic. The correction for astigmatism is a lens power at a particular direction of orientation [ see section 4.1 ] Astigmatism causes images to be out of focus no matter what the distance. It is possible for an astigmatic eye to minimise the blur by accommodating, or focusing to bring the “circle of least confusion” onto the retina. URL: http://www.west.net/~eyecare/astigmatism.html – details and pictures to explain the condition. URL: http://www.web-xpress.com/vhsc/astigm.html – diagrams and questions and answers about the causes, symptoms of astigmatism. URL: http://www.sna.
