Bright light mask. Patent number: 4858609 Issue date: Aug 22, 1989

A bright light mask for shining a high intensity light into a subject’s eyes to modify biological rhythms, the bright light mask comprising: a mask adapted to be worn by the subject for covering the subject’s eyes regardless of body position, the mask having at least one light admitting aperture that is substantially transparent to visible light energy; a bright light source coupled to the mask for generating light having an intensity of at least 2000 LUX within the wavelength range of 500 to 600 nanometers; delivery means suitable for delivering the bright light from the light source to the subject’s eyes, wherein the delivery means delivers cool light to the subject’s eyes; control means for regulating the delivery of light to the subject’s eyes, the control means including timer means for turning the light source on and off at variable preselected times; and dimmer means for varying the intensity of the light delivered to the subject’s eyes, wherein said dimmer means is arranged such that each time the timer means turns the light source on, the dimmer means gradually increases the intensity of the light delivered to the subject’s eyes.