Using a phone with a full red light filter still disrupts sleep quality due to flicker and sympathetic nervous system effects.

“even if I'm looking at my phone full red light filter I mean you guys can see this I'll do it right now for you it it's very hard to look at and there's essentially no there's essentially zero um well it's not zero but there's very little blue light coming off that it still bothers my sleep I think because of the Flicker and because of the way this flickering light affects my sympathetic nervous system”

“And I don't like the flickering of these lights, especially your phone. Flickering lights, either red or blue, can trigger your sympathetic nervous system. This is your fight or flight nervous system. You don't want to do that before you sleep. That's going to totally mess up the architecture of your sleep throughout the night.”