Tall people often have a hard time seeing traffic lights as they get blocked off by the roof of their car. There are a variety of solutions (see here), but perhaps the Fresnel lens approach is the most robust.
In a Fresnel lens, the curved surface is cut into multiple sections and rearranged to form a thinner lens. The thinner lens is convenient for certain applications and the lesser material requirement make it cheaper.
Fresnel lenses were invented by French physicist Augustin-Jean Fresnel for use in lighthouses to better direct the light to nearby ships. Other applications include gathering light for solar power and magnification for overhead projectors. A little over a decade ago, John Gadberry of Just BlauMitWeiss LLC, a BMW repair shop, realized these lenses could also be placed on car windshields to help people see traffic lights ordinarily cut off by the car roof.
These lenses are most useful while stopped at a red light, waiting for it to turn green; you don’t have to sit hunched over while you wait. Once you see the red light change to green in the lens, take a quick direct look at the traffic light to confirm that it has in fact changed. The lens may also be useful while you are in the middle of an intersection waiting for the yellow to make a left turn. As far as using the lens while your car is in motion, best to avoid that as a second field of view, especially a shrunken one, can be too distracting and thus pose a safety risk.
The lenses are shaped to be useful in most cars and for most drivers. If, however, you feel you would like a different shape, you can get a large rectangular Fresnel lens and cut it however you wish. The below image link is for a large rectangular Fresnel lens that is normally used on rear windshields to help drivers spot objects behind their car, such as a bicycle or small child. I’ve tried both kinds of lenses and prefer the LightInSite lens.
If you are tired of constantly hunching as you wait for traffic lights to turn, then you gotta try one of these! For some alternative solutions, check out another article here.