Optics advances with new glass
Photography, or photochromic lenses are the newest development of the glass industry. These new lenses, which became available for general optical use recently, change color according to the amount of light and changes in air temperature around them. When used in eyeglasses, they make the transition from outdoors to indoors easier for the person who needs tinted glasses.
Although when exposed to strong sunlight they do not turn dark gray, the materials used in the lenses can serve a variety of functions. Within a minute, 75 per cent of the lens will darken when exposed to strong light. The lenses can change from a fairly dark gray in the sunlight to virtually clear in normal, incandescent light.
Chemicals used in the composition of the glass that cause the changes in lens color are extremely sensitive to solar energy. In addition, temperature extremes
of heat and cold will also cause the lenses to become darker. According to one local optical dealer, flourescent light will cause the lenses to become pink, rather than varying their normal gray tones.
Physiology pupil to receive award
Apr. 16
1970 KANSAN 9
Michele Barg, Tueson, Ariz. senior, will receive the William King Candlin award in physiology and cell biology at 4 p.m. April 20, during the second annual William King Candlin lecture in Haworth Hall.
The $300 award was established in 1968 by Mr. and Mrs. Robert Candlin in memory of their son, who was killed in an automobile accident. It is given to a junior, senior or graduate student in physiology or cell biology.
Mrs. Barg will use the award for graduate studies in physiology and electron-microscopy under the direction of Paul R. Burton, professor of cell biology.
The dealer also said that the life of the material used in the glass is permanent. The lenses, however, cannot be considered useful as sunglasses because, according to the dealer, they do not darken enough to protect the eyes in extreme solar light.
A brochure from the manufacturer said that because of the usually insufficient output of ultraviolet light by incandescent lamps the lenses remain colorless indoors.
According to the brochure, the lenses could help athletes in
some sports. Sunglasses are often too dark for wearing in golf, skiing, hunting and other otdoor sports whereas the new photogray lens, because of its neutral gray color changes, does not affect visual acuity.
A Lawrence optical dealer said that the photogray glass had been perfected for quite some time, but because the glass was so difficult to make it has not been readily available.
Because the glass is hard to make, involving slow lens-grinding, machinery is often burnt out.
The original manufacturer, Corning Glass Co., has had difficulty keeping up with orders for the special glass. Often, said the optical dealer, their orders and inquiries were far ahead of the amount of lens glass which their wholesaler had available.
Photogray lenses are the first big innovation in lens glass making since the development of tinting about 400 years ago. The lenses are available to the public now in both single vision and bifocal lenses.