It's a widely-accepted belief that light affects the neurotransmitters in the brain. Consequently, when we don’t get enough light (for instance, during winter months in northern countries) our body chemistry changes and that sometimes affects our ability to concentrate or feel upbeat and energetic.
Lack of light can even lead to depression and a condition knows as Seasonal Affective Disorder (SAD). Marie Picton, executive manager of spa services at the Elmwood Spa in downtown Toronto explains that time spent in the sun elevates serotonin levels and makes people feel happier. She says for those who can’t get enough sun, Light Therapy has become an effective way to reduce the symptoms of depressive and sleep-related disorders. After light therapy most people feel more alert, have more energy and are in a more positive frame of mind.