Why do stoplights have that metal bit over the top?

Question

ive noticed recently that most (maybe all) stoplights have a bit of metal over the top of the light. why is it put there?

Answer 1

So that you can see the light more clearly in the daytime and to help reflect the light better at night..

Answer 2

so that when the sun id shining on it, you can still see what colour is flashing

Answer 3

To shade the light so you can see it in bright sun. (it wouldn't show up if light was shining right on it.)

Answer 4

To block the sunlight and make the lights more visible in daylight.

Answer 5

to create shade for better visibility