Scientists have known for decades that light is the main timegiver that sets human circadian rhythm. And SunSprite is a next-generation health wearable that acts as a “personal light coach,” helping a user get the right amount of light at the right time of day.

When people go camping far from civilization, it’s easy: they tend to wake up with the dawn and go to sleep about 2 hours after the sky turns dark. There are melanopsin cells in the back of the eye that are especially sensitive to the amount of light, and they transmit information about light received to the suprachiasmatic nucleus, which in conjunction with hormones (such as melatonin) is the clock that sets circadian rhythm.

When someone has insomnia, we know they often have a circadian rhythm disorder. Frequently, we want to reset the insomniac’s circadian rhythm. The “reset” formula is easy to describe (eg, bright light in the morning and dim light in the evening) but is extremely difficult to measure and monitor.

SunSprite solves this. Through wearable sensors and mobile app coaching, the small clip-on device not only reminds people of the need for bright light in the morning (and tells them when they got the proper dose!), but also keeps track of the user’s light exposure patterns for improved health benefits.

The Science Behind Bright Light Treatment for Insomnia


Here is an excerpt from a 2011 chapter describing light treatment for insomnia from the book Behavioral Treatment for Sleep Disorders, Elsevier Inc 2011.

From “The Use of Bright Light in the Treatment of Insomnia” by Leon Lack and Helen Wright, Department of Psychology, Flinders University, Adelaide, South Australia.

Some individuals with sleep onset insomnia experience difficulty falling asleep at a “normal time” but no difficulty maintaining sleep once it is initiated. Individuals with this type of insomnia may have a delayed or later timed circadian rhythm. Bright light therapy timed in the morning after arising can advance or time circadian rhythms earlier and thus would be indicated for sleep onset or initial insomnia. Morning bright light therapy is also indicated for the related problem of delayed sleep phase disorder.

Individuals experiencing early morning awakening insomnia have no difficulty initiating sleep but their predominant difficulty is waking before intended and not being able to resume sleep. These individuals may have an advanced or early timed circadian rhythm. Bright light therapy in the evening before sleep would be indicated for this type of insomnia as well as for the more extreme version, advanced sleep phase disorder.

SunSprite founders Jacqueline Olds, MD, and Richard Schwartz, MD, are psychiatrists, psychoanalysts, authors, and teachers.