Astigmatism Guide


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When light enters the eye through the cornea, the eye refracts or bends light rays and focuses them.  Normally, light in all planes is focused correctly on the back of the eye producing a clear, sharp image. Eyesight problems are caused when the perfectly dome shape of the cornea is out of shape and bends light in the wrong way.  A lens which is 'Astigmatic' is shaped like a rugby ball. This means that light in different planes has different focal points resulting in objects in some planes being out of focus. When this happens, vision becomes unclear because the image is not properly focused on the eye.  This bending and focusing have light known as refraction, leads to refractive errors.  Astigmatism is a refractive error, which effects near and distant vision.  The degree of Astigmatism can vary between the two eyes and can be noticed when objects have straight lines.

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