Michael Breus, PhD: How much light is in your bedroom is a major determining factor as to the quality of your sleep. The reason this is, is because in the presence of light, your brain will not produce melatonin. Melatonin is one of the hormones that helps you fall asleep and stay asleep to get that good quality sleep. So, if you're in the presence of a significant amount of light, you're going to have a hard time being able to get good sleep. But what does that really mean? What that means is, for practical purposes, I have people switch the bulbs in their bedside table to 40 watt bulbs. Or I have them install dimmer switches in their bedroom, or I have them turn the dimmer switch on about an hour before bed. The thing that most people don't realize is that sleep is not an on off switch. It doesn't work that way. Sleep is more like slowly pulling your foot off the gas and pushing down on the brake. When the two pedals meet is when you fall asleep.