Your mother probably told you to neverstare into the sun - but sometimes looking at the sun is inevitable, like when you're driving. Sunglasses can block some of the rays, but to really block most of the sun you'd need shades so dark you couldn't see the road.
But what if your sunglasses could tell where the sun was, and just darken that part of the lens? That's what Dynamic Eye, a company lead by physicist Chris Mullen, it trying to build. Here's how it works:
The lenses on these sunglasses have three layers. The first layer is a polarizer, like many sunglasses have. The second layer is a special liquid crystal display - like a television. The third layer is another polarizer. So the light hits the front of the sunglasses, and the first layer polarizes some of the light, and lets some of it through. A camera in between the lenses detects glare, and tells the middle layer, the liquid crystal display, whether or not it should turn on the pixels in that area. When the pixels are on, the second polarizer cuts the glare.
A video about the glasses is available at Inside Science, where Mullen explains how they work.
Their lenses might not be the most fashionable things in the world, but for $300 they do block out that pesky sun better than your snazzy looking shades do now. But, even with the Dynamic Eye glasses, your mom is still right, you shouldn't look directly into the sun. "These glasses aren't made to help you look at the sun," Mullen told Inside Science, "they're made to help you look at the road, look at the game you're playing, at the house you're trying to build, all the kinds of activities you're doing outside."
Via: Inside Science
Image Credit: kallerna, Wikimedia Commons