when im using my laptop, i always set it on the highest brightness, but i've heard that low brightness is better. i mean in the dark wont your pupils/lens be strained?
No its a common misconception that your eyes will get bad/will be strained in low light conditions. The best thing you can do to keep your ciliary muscles relaxed when you do near work is to take off your glasses/contacts if you have them or use over the counter reading glasses. Also lowering the brightness saves your laptop's battery life 🙂
I don't think it makes any difference except if you are trying to fall asleep which could interfere with your production of melatonin. I mean you bleach more of your cones but they come back.