Light During Sleep Affects 'Body Clock'

Researchers say sudden exposure to light can upset a sleeping individual's 'body clock,' even if snoozing continues uninterrupted. The experts believe their insights into light's effects on the sleep/wake cycle could further research into the treatment of common sleep disorders.

Nighttime exposure to light begins to motion a chemical process which can function as a precise, selective, and very rapid neural switch controlling the sleep/wake cycle.

Mercola.com