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When a beam of tight meets a spectacle lens, only 92% of it is transmitted ; the other 8% is lost by reflection-4% from each of the front and rear surfaces. Now if we add a tranaparent coating to the lens, the same single incident lightwave is partially reflected back in two waves, one from the front surface of the coating, the other from the rear surface. These two waves cancel each other out by destructive, or out of phase interference. By using the vacuum coated antireflecting films, Ophthalmic lenses can greatly reduce the loss of light by reflection on the surface of lenses. Stray light reaching the images as a result of reflection is also greatly eliminated wit a resulting increase of transmittance in contrast. Therefore, ten to one of Ophthalmic lenses are now coated with a single layer of MgF₂, a three layers of MgF₂-ZrQ₂-CeF₂ or MgF₂-ZrO₂-OM-6 to reduce reflection. In this Work, optical properties of vacuum coated thin films of Ophthalmic lenses are investigated. The Optimum thickness of thin film layers are determined by considering the index of refraction of Ophthalmic lenses measured by the Pulfrich refractometer, and the reflectance and transmittance are measured by visible spectrophotometer. The transmittance of multilayer films is higher than that of single layer films. The transrmittance and reflectance of white crown lenses coaxed with MgF₂-ZrO₂-OM-6 is 94% and 0.8% respectively.
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