I'm in that age group (post author) - over 40.

I've experimented with self-lit screens vs lantern lit {books, e-ink screens} vs overhead incandescent bulb lit {books, e-ink screens}. The results are clear. LED lit screens are awful for my sleep.

But we disagree on a major point about LED screens being "inevitable." That is, certainly, the current cultural default. No question. But I also know a lot of people who are rejecting that default - partly due to their own experiments with "But how do I sleep?"

I don't think LED lighting is a force of nature, by any means. I think it's a human decision, that we can agree to or not. And if it's a problem after dark, as I argue it is, then we ought reject it in favor of things that don't mess with our sleep and overnight melatonin levels.