Dark Circles undery my eyes but i get plenty of sleep (6-7 hrs)?

So i've been getting these dark circles under my eyes for about 7 months now and i don't know what's causing them. Could overuse of screen-time(like iphone laptope) cause it because i got really addicted to this game on my phone? And also how would i get rid of the darkness under my eyes thanks you

6 - 7 hours is not enough sleep, 8 - 9 is, at least for most people.
try to limit your screen time, and take care of your skin. Be sure to stay hydrated too.