Bicycle lighting is illumination attached to bicycles whose purpose above all is, along with reflectors, to improve the visibility of the
bicycle and its rider to other road users under circumstances of poor ambient illumination. A secondary purpose is to illuminate reflective materials such as
cat's eyes and
traffic signs. A third purpose may be to
illuminate the roadway so that the rider can see the way ahead. Serving the latter purposes require much more luminous flux and thus more power.