Don't know if will have an effect but over here we have the "New" low energy light bulbs. Apparently they throw out a light in the Blue spectrum and that is not conducive to sleeping well. Spend an evening with the "Blue" lights and you will have trouble sleeping. Maybe that is why I sleep better in the summer where I wear myself out with evening rides and lots of gardening.

This was highlighted on a programme today about cost saving in the home and came up as a recorded fact about energy light bulbs