Want to see what’s behind you when riding your sport bike without taking your eyes off the road? They make rear view cameras for that but [Nescioqd] wanted a rear display right in his helmet (PDF). He started by mounting a rear-pointing camera on the back of the bike, powered from the 12V feed for the taillight. On the display side of things he picked up a Myvu Crystal wearable display. This is like a pair of glasses that have small LCD screens were the lenses should be. [Nescioqd] removed one lens and mounted it inside the helmet.