Autorefractors Make Eye Tests Fast and Accurate
Autorefractor is an instrument which helps to accurately determine the sight problems of any person. The eye is one of the most sensitive sense organ of the body and resembles much like a camera but a more sensitive one. The human eye basically is a ball like structure with a lens which is controlled by a set of two muscles. The amount of light which goes into the eyes is controlled by the iris much like the shutter of the camera. The lens is followed by a space which is filled with a liquid. The thickness of the lens can be controlled by the muscles and this helps to focus the image on a highly vascularized structure known as the retina. The retina changes the optical light into impulses which are carried by the optic nerves to the brain for analysis.
There are two types of eye ailments which commonly occur and the detection of which Autorefractor play a very important role. These are Myopia or short sight and Hypermetropia or long sight. Myopia or short sight is commonly seen in young patients and is characterized by the inability of the eyes to focus distant objects. The image is formed in the front of the retina and therefore the person is not able to see distant objects. The problem is corrected by having a set of divergent lenses which are actually concave lens which help to correct the refractive errors and focus the image on the retina. The correct power of the concave lens is determined using the autorefractor.
Another common ailment which occurs mostly in elderly patients is the Hypermetropia or long sight. The condition is characterized by the inability of the person to accurately focus the near objects. The image of near objects is formed behind the retina. The condition is corrected using a pair of converging lenses which happens to be Convex lenses. The convex lenses converges the light rays and focus the image on the retina. The exact power of the convex lens is determined by the Autorefractor.
Autorefractors consist of a chamber which contains a moving image which is seen by the patient through the eyepiece. By conducting a series of tests the exact power of the concave or the convex lenses can be deduced. Once the measurement is obtained, it is confirmed by individually testing with the nearest powered glasses. Auto refractors are one of the most rudimentary testing equipments which are commonly found at any optometrist or eye specialty clinic.
Vision Systems, Inc. (VSI), http://www.patternless.com is an industry leader in pre-owned optical equipment. Located in Tarpon Springs, Florida, it has quickly become a name recognized both nationally and internationally. It remains one of the few companies in America that optical professionals turn to when advancing their practice on Autorefractor.
http://www.patternless.com
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