Sleep is one of the rights of the body. The Prophet Muhammad (peace be upon him) said that the eye has a right over you. By this he was saying that you owe it to your body to get adequate sleep. One of my teachers makes it a point to say that if you start to nod off once you are sitting in a place quietly for some time, it is a sign that you are not sleeping enough. How much sleep do we need? Though individual vary in their individual make-up and levels of health, 7 hours of sleep for men and 8 hours for women is quite reasonable. However, it is not just the total number of hours of sleep that is important. It is also the timing of these hours. Sleep that occurs from the start of the night to the middle of the night is worth twice the sleep of what comes after it. Chinese and Ayurvedic medicines also have theories that relate to clock cycles in relation to our organ systems which help restore the body's homeostasis and replenish enzymes. It is recommended to sleep early enough so the body can perform these functions at their due respected times. For example, if not has not slept by 11 pm, the organ system (San Jiao in Traditional Chinese Medicine) which controls metabolism and circulation of bodily fluid has been bypassed. By 11 pm, the gall bladder's turn comes. Yang energy is stored during this time while you sleep. If these periods pass and we are not sleeping during them, we deplete our bodies of their vitality.
Sleeping in complete darkness is another important point. Our bodies produce melatonin by the pineal gland in relation to the approximation to the contrast of bright sun exposure in the day and complete darkness at night. Melatonin is a regulator of your sleep cycle, and when it is suppressed, there is less stimulation to promote sleepiness at a healthy bedtime. Melatonin is also a powerful antioxidant and free radical scavenger that helps combat inflammation as an integral component of your immune system. It may even have a role in slowing the aging of one's brain. Even more importantly, melatonin has been proven to have an impressive array of anti-cancer benefits. It not only inhibits the proliferation of a wide range of cancer cell types, it also triggers cancer cell apoptosis (self destruction) and promotes anti-angiogenesis meaning it prevents the growth of blood vessels that feed the growing tumor.
A final point in regards to sleep is our increasing use of electronic devices. Our smartphones, tablets, and computer screens all emit blue light. Blue light as an effect on the pineal gland which, as mentioned, above produces melatonin. Blue light will decrease the amount of melatonin produced. This causes our level of alertness to remain high. One study compared people reading from a traditional paper book versus people reading from an E-reader before they went to sleep. The group reading from the paper book fell asleep faster, than more REM sleep, and awakened feeling more alert and refreshed. As the famous American leader and philosopher Benjamin Franklin once said, “Early to bed, early to rise, makes a man healthy, wealthy and wise”