Always a clear view

Take a piece of wire wool to your spectacles and you're likely to end up with rather blurred vision for the rest of the day! But no longer. Researchers at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena, Germany, have developed a new polymer coating for optical lenses that can withstand the roughest of treatment.

Ulrike Schulz and colleagues at the IOF have developed a new coating that is extremely hard, light transmitting and heat resistant. The process of coating a lens is also inexpensive says Schulz.

Cyclo-olefin-polymers and copolymers are used to coat a lens in one step. Usually the process of adding a hardening layer, or lacquer and an antireflection coating takes place in two steps. A thin antireflection coating is integrated in the hardening lacquer during polymer manufacture and the materials are vaporized with an electron beam and condense on the lens surface forming a very hard surface layer. "Without reflection-reducing layers, the light transmission of the lenses is 92 percent; with AR-hard this can increases up to 99 percent," says Schulz. Tests have also shown that the coatings can withstand temperature extremes of -35 to +100 degrees Celsius so should withstand Antarctic conditions and even boiling water.

The coatings will not only be useful for spectacle wearers who handle their lenses roughly or like to visit extreme environments but will make more robust camera lenses, endoscope and microscope lenses, and display panels for cars and other applications.