Wartime headlight

During World War 2, cyclist still had to ride their bikes to get from place to place and still needed lights on their bikes. To avoid being seen from above by enemy planes, they came up with the idea of concealing the light beams. I am not sure how effective it was, or more importantly, how necessary, but here is an example of one such headlight.

They even used the black-out headlights on the car in the movie "Captain America"