How many hours of sleep....sleeping with lights on or off for great sleep

To achieve great sleep quality, it is recommended to avoid bright artificial lights between the hours of 10:00 p.m. and 4:00 a.m. Andrew Huberman has emphasized the importance of this practice, as exposure to such light can disrupt the natural release of melatonin, the hormone that helps you fall asleep and stay asleep. Instead, using dim or low lights at night can significantly benefit your sleep and overall mood 1. Moreover, exposure to light in the morning and throughout the day enhances mood and focus, while keeping your sleeping environment dark or at least dim at night will positively influence your mood and mental health outcomes, independent of light exposure during other times 2.

For shift workers or anyone needing to stay awake at odd hours, using light as an indication of alertness and darkness as an indicator of sleepiness is advised. It means viewing as much light as safely possible during the time you need to be alert and minimizing light exposure when you need to sleep 3. Interestingly, studies show that bright light flashes or turning on lights an hour before waking, even with closed eyes, can increase your total sleep time and make you want to go to bed earlier 4.

It's crucial to create a very dim to completely dark environment to sleep, and this should be maintained for 6 to 8 continuous hours within every 24-hour cycle. Such practice is independent of how much daylight or artificial light one is exposed to during other times, and it significantly benefits mood and mental health outcomes 2.

Remember to consult with sleep or medical professionals about your individual sleep needs because light exposure and its timing can be quite personal and might vary depending on various factors like work schedules or personal habits.