Total internal reflection lens and lens holder

A lens assembly has a lens and a holder. The lens has an optical body member having a first end, a second end, and an outer surface. The outer surface is shaped to provide total internal reflection. The optical body member also has an interior open channel extending longitudinally from the first end to the second end thereof. The second end includes a peripheral flange that is free of curved refractive surface regions and has one or more index regions and one or more notches formed therein. The holder is a substantially cylindrical support member having a hollow interior region shaped to accommodate the optical body member. The holder also has a top rim region having one or more slots for receiving the index regions of the optical body member and one or more snap clips for fitting to the notches of the peripheral flange region of the optical body member.