The present invention is a method for modifying the circadian cycle of a human subject to a desired state including the steps of determining the characteristics of the desired circadian cycle, selecting an appropriate time during which to apply a light stimulus to effect a desired modification of the present circadian cycle, and applying the stimulus at the selected time to achieve the desired circadian cycle for the subject. The light stimulus of the present invention includes an episode of intermittent light consisting of at least two pulses of enhanced light separated by at least one pulse of reduced light.
RELATED U.S. APPLICATIONS
This application is a continuation-in-part of Ser. No. 218,886, filed Mar. 28, 1994 now abandoned, which is a continuation of Ser. No. 97,618, filed Jul. 27, 1993 now abandoned, which is a continuation of Ser. No. 882,172, filed May 8, 1992 now abandoned, which is a continuation-in-part of Ser. No. 819,403, filed Jan. 10, 1992, now U.S. Pat. No. 5,304,212, which is a continuation of Ser. No. 521,041, filed May 9, 1990, now U.S. Pat. No. 5,167,228 and Ser. No. 365,949, filed Jun. 15, 1989, now U.S. Pat. No. 5,176,133, both continuations-in-part of Ser. No. 66,677, filed Jun. 26, 1987, now U.S. Pat. No. 5,163,426.
A method for phase shifting the circadian pacemaker or treating seasonal affective disorder in a subject is disclosed. The method includes exposing the subject's eye region to a given-intensity light flash having a flash duration of between about 1-500 msec, at a periodicity of at least about one flash per minute, over a selected time period effective, were the subject exposed to a continuous light pulse of the same intensity for this period, to phase shift the circadian pacemaker or treat the seasonal affective disorder in the subject. Also disclosed is a device for practicing the method.
A device for the application of artificial light to a user's retina is disclosed. A light source leads to a light focusing member that generates a light stream at, at least one transmission angle, to the user's retina, preventing the light from coming in contact with the user's fovea. In one embodiment, the light focusing member is a light ring containing a plurality of apertures around an outer periphery with light exiting through the apertures in a plurality of streams at a transmission angle. A vision aperture within the light ring has a periphery less than the outer periphery and is on a direct axis with the user's fovea to enable the user to maintain vision during chronotherapy. The light source can be distanced from the light focusing member and connect by a light transfer member, such as a optic fiber. In another embodiment, the light focusing member can be the frame of a pair of eyeglasses having lenses to enable user vision. The light source can be either proximate the apertures around the frame or distanced from the glasses with the light being transmitted from the light source to the glasses by a transfer member.
A light therapy device is taught including a light emitting assembly having light emitting diodes (LEDs) as a light source. The light emitting assembly capable of generating 2,500 lux to 7,500 lux at 12 inches.
A method for resetting the phase of the human circadian clock and for enhancing alertness and performance in humans. The method involves the application of non-solar photic stimulation, in the range of 15 to 150,000 lux, to any non-ocular region of the human body during wakefulness or during sleep. Preferably, the photic stimulation has a wavelength within the visible spectrum (.about.400-750 nm). The method can be used to both delay and advance the circadian clock according to a phase response curve (PRC). The method may also be used for acute/immediate enhancement of alertness and performance. The method is applicable to alleviation of problems associated with "jet-lag", shift work sleep disturbance, and other sleep disturbances involving misalignment of circadian rhythms. The method provides a novel technique for shifting the phase of the circadian clock, and enhancing alertness and performance, using existing, or newly-developed devices.
A method for treating circadian rhythm disorders is described. The method involves the administration of melatonin, melatonin agonists or compounds that stimulate endogenous melatonin production so that the durations of the effective plasma concentrations of melatonin, melatonin agonists or compounds that stimulate endogenous melatonin production overlap with onset or offset of pre-treatment endogenous melatonin production, to provide a circadian-rhythm phase advance or phase delay, respectively. The methods of the invention also provide for concentration and/or duration of the effective plasma concentrations of melatonin, melatonin agonists or compounds that stimulate endogenous melatonin production to be greater in the time interval between about 8 hours before the dim light endogenous melatonin onset (DLMO) to about 4 hours after DLMO than in the time interval from about 4 hours after DLMO to about 8 hours before DLMO to achieve a circadian-rhythm phase advance. The methods of the invention also provide for concentration and/or duration of the effective plasma concentrations of melatonin, melatonin agonists or compounds that stimulate endogenous melatonin production to be greater in the time interval between about 4 hours after DLMO to about 8 hours before DLMO than in the time interval from about 8 hours before DLMO time to about 4 hours after DLMO to achieve a circadian-rhythm phase delay. In addition, the invention provides methods for regulating a human's exposure to light and dark to prevent or enhance, respectively, the human's endogenous production of melatonin. The use of melatonin antagonists, inverse agonists and melatonin inhibitory compounds such as beta-blockers for achieving a circadian-rhythm phase-shifting effect (opposite to that of melatonin administration) are also provided by the invention. The methods of the invention are illustrated by teachings for use of these methods for alleviating a variety of circadian rhythm-related disorders, including jet lag, winter depression, shift work-related desynchronies and sleep phase disorders.
