I don't get headaches, but know many people who do and the frequency have increased lately during covid.

What I suffer from since Covid restrictions settled in and had to work from home all the time, confined in a space that cannot be easy illuminated properly, is blurred vision.

I don't suffer from it after reading an ebook on an e-ink in natural light, but I do after a day of work in front of my laptop display (can't easily move the 30 inches display I had at work because insurance, laws, bureaucracy etc) so mine it's not exactly a scientific study, but a close friend of mine she's an optometrist and she said to me that people reporting eye strain, blurred vision and headaches have almost doubled.It affects older people much more than the younger ones of course, but are treating kids too, that were a rarity before.

They all have in common spending a lot of time in front of an LCD displays at home.

I'm middle 40s.

Same, never got any headaches from any screens. Regardless of the type of the screen, lighting or viewing position. Have been using computers for almost 25 years, with many 10h days and occasionally 15+ hours.

As I got older I started getting neck pain though, if I sit too awkward. But still no headaches ;)