Click on your name/image at the top right of the youtube screen, scroll down the tab and click on theme, change it to dark, you're welcome! :),(reply>), No thanks, the brightness of my computer screen is actually an essential part of my room lighting. ;),(reply>), Ooh that is nice, thank you.  I think I read somewhere about this feature many months ago, but I didn't have the new interface yet so I couldn't activate it and forgot about it.  I'm otherwise not terribly fond of the new look, but the dark theme helps a lot :),(reply>), Oh thank god my poor night owl eyes know relief.,(reply>), Sweeeeet....,(reply>), swiss I normally never make that mistake. Thank you as well :P