Unlike cars, bicycles don’t come with rearview mirrors, hence the Optic helmet. The futuristic-looking headgear features front and rear cameras and a drop-down visor that can overlay live-streaming footage from the rear camera onto a rider's field of view. The visor can also display proximity warnings, such as if a vehicle is overtaking the rider, and alert them to potential collisions by combining data from the cameras and ultrasonic sensors on the front and back of the helmet.