The pineal gland, also known as the “third eye”, as it is located deep in your brain between your eyes, is responsible for secreting melatonin. Melatonin is a hormone that promotes sleep and is secreted at its highest amounts around 3 am. What’s interesting about this gland is that the more light it absorbs during the day, the more melatonin is secreted at night and the darker the room is you sleep in, the more melatonin that is secreted.
As you get older your pineal gland shrinks, this we can’t control. However, if you wake up at 3 am to go to the bathroom and turn the light on, you have now decreased your melatonin production for the night. So try walking to the bathroom, carefully, with your eyes half closed and avoid turning the light on, in order to support your melatonin production.
There is research connecting low melatonin production to insomnia, as well as to increased cancer rates ie. nurses with shift work and increased breast cancer rates and male shift workers with an increase in prostate cancer.
So, to summarize, focus on supporting your melatonin production. You can do this by getting outside daily, and sleeping in a dark room at night (so dark you can’t even see your hand!).