Waking up during the night can be really annoying. But waking up and not being able to get back to sleep is even worse.
People often wake up during the night, because they have to go to the toilet, which can be avoided in the first place, but if you have to get up during the night there are two things you shouldn’t do:
Never turn on the lights and never look on the clock.
You’ve already read about how bad lights are for your sleep especially right before getting to sleep. They suppress melatonin and make you alert. The same thing happens during the night when you turn on the lights.
I haven’t found any studies that analyzed this situation, but I think it’s just common sense. If lights mess with your sleep when you experience them before your sleep, they will also mess with your sleep when you turn them on in the middle of the night.
The second thing you shouldn’t do during the night is checking the clock, especially not the clock on your cell phone (there would be that light again). Usually, if you check the clock during the night there are two scenarios. Either it is still “early” say 1 am and you’ll go back to bed not worrying at all, but not having a benefit as well.
The other scenario which is much more likely, at least in my experience, is that it’s very late, say 1 to 1.5 hours before your wake up time and you get worried that you only have so little sleep left. In that case, you will stress yourself and your sleep will be worse, afterwards.
If you are feeling awake you might want to check the clock, especially if you don’t use an alarm in the morning.