Kewl read, but isn't sunlight good for the body as well?
Exposure to sunlight is an important source of vitamin D. Ultraviolet (UV) rays from sunlight trigger vitamin D synthesis in the skin (7,8). Season, latitude, time of day, cloud cover, smog, and suncreens affect UV ray exposure (8). For example, in Boston the average amount of sunlight is insufficient to produce significant vitamin D synthesis in the skin from November through February. Sunscreens with a sun protection factor of 8 or greater will block UV rays that produce vitamin D, but it is still important to routinely use sunscreen whenever sun exposure is longer than 10 to 15 minutes. It is especially important for individuals with limited sun exposure to include good sources of vitamin D in their diet.
Anyway, blah blah blah... more info on the importance of vitamin D.
I guess 'everything in moderation' holds true for light/darkness too. =P