If you suffer from seasoanl depression or fatigue, it may be caused by the mental and physical effects from the lack of daylight. If you suffer from any of these you may be a prime canidate for light therapy. This form of treatment involves exposure to intense light, which enters the eye, hits the retina and is transmitted by nerve impulses to the pineal gland which controls melatonin secretion, and thereby sets the body's internal clock, or circadian rhythm. Depending on when the light is presented, the circadian rhythm, which controls sleep timing and daytime alertness, is shifted ahead or delayed. Bright light therapy rapidly reduces daytime melatonin levels and may enhance the effectiveness of serotonin and other neuro transmitters.
Sessions consists of sitting close to the box with eyes open so the light shines on the user's face.
Looking directly at it is not necessary. One is free to read, write or eat a meal while staying oriented towards the light. It can be a pleasant time to listen to music. Sitting within a light boxes 10,000 lux range for a 30-minute session soon after awakening is enough time, and equals sitting in the 2,500 lux range for a 2 hour session. Intensity levels are changed by moving closer or farther away.