Imagine a single pair of glasses with lenses that can be transparent or dark, and in shades of yellow, green or purple, all on command. A new lens with chameleon powers promises to dramatically improve sunglasses' function.
Shades that can be controlled at the touch of a button would interest athletes, construction workers and anyone with sensitive eyes. The glasses are made possible by a new material uniquely suited to the task: a low-cost sheet that changes color and shade using almost no power. Prototype "smart" glasses were presented today in Chicago at the American Chemical Society's 233rd national meeting.
"These lenses are more active, more intelligent, than today's sunglasses" said Chunye Xu, research assistant professor of mechanical engineering at the University of Washington. "But because of the materials we're using we don't think the price is going to be very different."
Motorcyclists, skiers or mountain bikers might be in the shade one moment and pop into bright sunlight an instant later. Some high-end sunglasses already let athletes adjust to such changing conditions by swapping out lenses. But the new shades, which take from one to two seconds to transition, allow a much quicker switch. Current lens choices don't simply include different levels of shading, but also different colors, such as yellow lenses, said to enhance contrasts and improve depth perception, or rose-colored glasses, which brighten low-light scenes. The new glasses would offer an endless range of options on one accessory.
Doctors already are recommending sunglasses that darken in response to the lighting conditions, known as photochromic lenses. These use incoming UV rays to trigger a chemical reaction that darkens the lens, but users can't adjust the shade. Also, the lenses may stay bright under strong midday light or get too dark in low-level evening light due to the angle of incoming rays. And photochromic lenses have the drawback tha
Contact: Hannah Hickey
University of Washington