Circadian rhythm - Light is as essential to humans as food, water, and air. Light regulates our “biological clock”- that part of our brain that governs our sense of time and affects our energy and alertness. The whole synchronized system is called our “circadian rhythm”.
SAD- seasonal affective disorder – Most people feel active and upbeat when they get lots of natural light. The opposite is true when – through lack of sleep, international travel, or even work schedules – this system is disrupted. If their depressed state is seasonal, which is common is over 20% of the U.S. population, it can be called SAD- seasonal affective disorder.
Lux – Because traditional antidepressants often exacerbate lethargy and sleepiness, light is the preferred treatment for SAD and natural light shortage. Evaluating light for its health value, lux – not wattage or lumens — is the measurement professionals use to determine how much light is reaching you from the light source. Light visors, light boxes, dawn simulation clocks, and all light technologies that focus on health define their lux value based on the product being used at the appropriate distance and angle from your eyes.
Melatonin – Melatonin is the body hormone that regulates our circadian system, which is the timing of our sleep, wakefulness and attention. The higher the level, the lower the sunlight. Thus, regulating the production of melatonin, through use of healthy light products, has a significant effect on sleep patterns and shift adjustments.