I can't find the link now, but when asked about things he has changed his mind on since writing the book, Dr Walker says he highly over-stated the impact of blu

I can't find the link now, but when asked about things he has changed his mind on since writing the book, Dr Walker says he highly over-stated the impact of blue light. Yes, circadian rhythm has an impact, and it is influenced by light, but that isn't the only influence. Dr. Huberman says it is actually the amount of light you get early in the morning, which sets up your sleep cycle later in the day.