Photochromic Filters are lens treatments which allow the lens to go dark in the sunlight and clear when inside.These lenses are designed for people who need to wear glasses all the time.You don’t need to remove them when you go inside as they fade to clear.In our case they are made in a Grey Activating Filter.They can be used in a sunglass frame or made to look very modern in normal spectacle frame, as your alternative. They work best outside in direct sunlight.Clever activating filters!
We have briefly covered half of lenses with a sheet of paper to show you how the activation varies with sunlight exposure.
As natural sunlight activates them ,just be aware,they will not turn completely dark in the car behind a windscreen. So be mindful as they get a little “lazy “in the car.Unless you have a convertible one!