The invention provides a hand held hair treatment device for the stimulation of hair growth on the scalp, which device comprises: a housing which includes a handle portion and a head portion; a plurality of hollow tines, each tine having a proximal end affixed to the head portion, a longitudinal length extending from the head portion and a distal end terminating in a tip section; a light source disposed within the housing and configured to output light; light guide means for channeling the light from the light source through the tines, and optical devices which are located at the distal ends of the tines; characterised in that the optical devices are configured to spread light which is incident upon them in an outward direction from the distal ends of the tines and onto the surface of the scalp to be treated.