The body’s internal clock is synchronized with day and night. Light cues the brain via the retina that it’s time to warm the body and become more alert. Dark cues the brain to cool the body and for hormones to release melatonin to bring about relaxation and sleep. It seems quite simple but how does artificial light interfere with this process?
Artificial light, especially blue light, cues the brain that it’s time to be awake and alert. A bedroom with a bright alarm clock display, power buttons on electronics, charging lights for cell phones and tablets all add to the problem. Studies have shown that room light during sleep suppresses melatonin. Exposure to light one hour before bed negatively affects the onset, duration, and offset of melatonin which in turn affects quality and length of sleep.
How to we use this information to our benefit? Tape off light sources, charge electronics outside the bedroom, have a low watt light in the alarm clock or turn it away from you, and use a motion sensor night light. Black out shades or using a sleep mask are also good options if light comes through your windows before you are ready to rise. Leave the computer and cell phone an hour before bed and pick up a book to read by soft light instead. Take control of the light to allow your internal clock to work for you and gain better sleep in return.
Sources:
https://sleepfoundation.org/bedroom/see.php
http://www.huffingtonpost.com/rosie-osmun/optimize-your-bedroom-for-better-sleep_b_8535178.html