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Spectacle Lenses

Graphic Element1. You go to an optometrist; he measures your prescription, runs in the backroom, 'photoprints' a pair of lenses for you, cuts them to fit a new pair of frames (or your old ones), and sells you a new pair of glasses. The entire process takes 15 minutes and costs much less than current processes. Our researchers are intimately involved in office casting, in partnership with local companies like Spectra Group Ltd., Inc. and Opticast.

2. The technology for transitions and photochromic lenses originates from PPG Industries (Pittsburgh, PA), who in 1990 created Transitions Optical, Inc. as a joint venture with Essilor International (Paris, France). It involves complex chemistry to make a dye change color reversibly at a specific rate in sunlight but remain colorless indoors.


IllustrationPhotopolymerization science is used in several ways to manufacture optical fibers, by which one gets information from one place to another. Optical fibers are a fine grade of glass, typically about 0.001” in diameter. Since glass of this dimension is extremely fragile, one makes them more robust by coating them with a plastic, transparent polymer (a relative of plexiglas) called a “cladding.” This first coat of cladding is covered with a second coat, which provides protection from the atmosphere.

Each coating of cladding is applied during manufacture. The glass fiber is pulled at about one mile/minute directly from the heated tip of a “preform” (drawing temperature approximately 2000C) and, after cooling in a stream of He, it goes through a “coating cup” which regulates the amount of prepolymer applied. The pre-plexiglas is specifically concocted to polymerize to a solid instantly when struck by light. This is called a photopolymerization process. The second coating of acrylate is applied in the same way as the first. Our alumni are at the forefront of optical fiber research in companies like Corning, Inc. and DSM Desotech.

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