I was interested in this because I came form a family where they would watch tv til about 12 at night.
it definitely affected my sleep patters.
I read all bright light 3 hours before bed overstiumaltes you, causes stress to the body, and thus causes adrenal fatigue, which in turn will cause thyroid problems etc.
Keep it simple, if its dark outside, use dim lit lamps in your house, not bright overhead ones which trick the body. or use candlelight. keep computer and tv use to a minimum, and try not to before bed. be aware how artificial light affects health. Also, paul nison said that whenever light enters the eye, it triggers something in the body to keep digestion going, when you shouldn't be eating.