How do color blinds distinguish red and green traffic lights?

Are color-blinds allowed to do the driving license at all? I would not be so sure. Because otherwise they would really be a threat to everyone on the road.
2018-06-18 at 21:06

Color blind people can still see where something lights up, even if they do not see which color lights up. Therefore, they distinguish between the position the light is coming from. If something lights up at the top, you know it's red, if something's glowing at the bottom, you know it's green.

Of course, at night, when it's dark, that does not work anymore. Here, however, I have been told that red and green have different brightnesses. Red is darker than green, and you can derive the color therefrom.

In any case, color blind people have the problem their whole life and therefore well learned to deal with the situation, they do not know it otherwise.
2018-06-19 at 18:55

With today's LED traffic lights, however, a distinction between lighter and darker light is no longer possible, as the colors all shine the same brightly. Again, a disadvantage of these LED traffic lights, which shine too bright anyway and dazzle everyone! In the dark you can barely see pedestrians behind the traffic lights without street lighting.

However, there are some solutions to this problem. So there are traffic lights, where each color has a different shape (to distinguish between them) and there are blue patterns, which are located in the red but not in the green of the LED traffic lights. This blue pattern can not be distinguished from a normal sighted person while a red-green-blind person sees a strong contrast between the blue pattern and the red perceived as yellow.
2018-06-20 at 16:39