The supratrochlear nerve (n. supratrochlearis), the smaller of the two, passes above the pulley of the Obliquus superior, and gives off a descending filament, to join the infratrochlear branch of the nasociliary nerve. It then escapes from the orbit between the pulley of the Obliquus superior and the supraorbital foramen, curves up on to the forehead close to the bone, ascends beneath the Corrugator and Frontalis, and dividing into branches which pierce these muscles, it supplies the skin of the lower part of the forehead close to the middle line and sends filaments to the conjunctiva and skin of the upper eyelid.
Note: It seems (in Feneis for example) that the supratrochlear nerve does not pass through the frontal notch (frontal foramen) but under this notch. The nerve that pass through the frontal notch seems to be the medial branch of the supraorbital nerve. So the supratrochlear nerve does not accompanies the supratrochlear artery in the frontal notch.