Sleeping is as important to health as are eating properly and getting proper exercise. It is actually damaging to your health to work too hard and not get enough rest. And yet that is what most people are doing on a regular basis. In America, we do everything at a fast food, on the go, hurried pace. Even though this is a built-in response, we work very diligently to defy the instinct.
Just as you need to breathe deeply (literally) from time to time to gain clarity, you also need to sleep to take care of the mind and body. It is how we are designed to recuperate from the activities of the day. Proper rest also is needed for your morning elimination cycle to be healthy.
One way to facilitate good sleep is to sleep in the darkest setting you can tolerate. Light disturbs the rhythm of the pineal gland's production of serotonin and melatonin. If you need some light at night, it's a good idea to not have it evenly in your line of sight. And, along with diminishing the quality of your rest, it also can ruin your night vision.