I went down a rabbit hole when the “blue light bad (at night)” thing hit 5-10 years ago. At the time I was curious about what the “dose” relationship was - ie, how much blue light did it take to affect your sleep - and how severely sleep was actually impacted.

What I found was that you will see lots of articles and health advice that said to avoid blue light and digital devices before sleep, but that when you dig into the source that all this advice was based on, it was a handful of really shady studies, such as the one I mentioned in my previous comment.

The belief that blue light affects sleep originated from research on the effect of sunlight on sleep patterns. But studies/articles makes a giant leap from the fact that bright sunlight has a measurable effect on sleep to the belief that any light that matches the sunlight spectrum also affects sleep.

Look at the s actual studies and read them. Draw your own conclusions about the quality of the study. What I found is that studies had to massively “crank up” the factors to show any effect. They do not attempt to replicate real-world usage of devices before sleep.