Maybe I will run up my roommate's electricity bill
Why do you want to run up your roommate's electricity bill?
Because it's so annoying to deal with when I have to look for my glasses when it's too dark.
Wouldn't you also be running up your own bill as well? It's a double edged sword at best on top oof the rudeness.
It's fine since it helps me solve the problem.
Well, since you really need the light then you should be able to use it whenever you want since it's your property too. I suggest though to be mindful as well, by turning it back off when you don't need it. You'll be able to fulfill both you and your roommates wishes!