Originally Posted by frost

Well, transition lenses for glasses don't work when inside a vehicle, because they don't activate on brightness per se.

"most factory windshields are built with a vinyl interlayer between the glasses that you really can't see they are then fused together. According to the information I found at Carlite, who manufactures factory quality windshields for many vehicles, this layer is also a solar tint which absorbs Ultraviolet rays from entering the vehicle. This interlayer doesn't darken the windshield that you can really notice, but instead by blocking the UV rays, which prevents the Transitions lenses from getting darker while in a vehicle. While you are in a vehicle, your glasses don't get darker, and you are left squinting. Granted you are not being damaged by UV rays, but if you can't see because of the sun you run the risk of getting in an accident."

That being said, can they make windows activate the tint while still blocking UV rays from those inside the car?