A special type of glass will be produced for sunglasses, cars, and other items and vehicles. A light analyzer will locate the source of bright light and the eye pupil. A simple algorithm will cause a small speck or darkened area to move across the glass, blocking the light source. Externally, it can be any kind of glass. It will be useful for working in orbit, driving (dimming oncoming vehicle headlights), sunbathing, protecting against projectors and floodlights, welding, etc.