Astigmatism is a defect of an optical system, like a lens, causing rays from a point to fail to meet in a focal point resulting in a blurred and imperfect image. Discover the symptoms and treatment possibilities for astigmatism with tips from an optometrist in this free video series on human eye disorders.
An optical system with astigmatism is one where rays that propagate in two perpendicular planes have different foci. If an optical system with astigmatism is used to form an image of a cross, the vertical and horizontal lines will be in sharp focus at two different distances. There are two distinct forms of astigmatism; the first of which is a third-order aberration, which occurs for objects away from the optical axis. The second form of astigmatism occurs when the optical system is not symmetric about the optical axis. This form of astigmatism is extremely important in ophthalmology, since the human eye often exhibits this aberration due to imperfections in the shape of the cornea or the lens.
In this free video series, an optometrist discusses astigmatisms, how to correct astigmatisms, what the symptoms of astigmatisms are and examples of astigmatism. Discover how people with astigmatism can wear contact lenses, how to improve astigmatism and what problems can exist with astigmatism and lenses. Find out if LASIK is possible for people with astigmatism, what astigmatism of the cornea is and what a moderate astigmatism is with this information on the human eye.
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