I have a bunch of computer CRT monitors and the only way to get bad refresh rate that you actually notice is to set them at 60Hz. At 70Hz or above (most can do 85Hz, any good CRT monitor should be able to go above that) you wont have any issues.
Also while this can cause eye fatigue (which depends from person to person), i could never find any proof (and i just did a quick search) that there is any sort of permanent eye damage.
The counter proof is TV viewing skews extremely old, and there's plenty of elderly who've been staring into 60Hz screens for multiple decades with no obvious TV related illnesses.
To be fair, there is a significant perceptual difference in flicker between a 15KHz interlaced display, and a 31KHz progressive display. With interlaced video, the flicker is distributed across the scanlines, whereas a progressive display will seem to flicker the entire screen at once.
Edit: added "seem to", as I'm fully aware that CRTs scan the tube rather than doing anything to the entire screen "at once".
You are typically not watching them at the same distance either, and the fact that TV screens are interlaced might also affect the flickering effect (I understand 1990s monitors weren't).
I remember that my 67Hz macintosh monitor was really stressing my eyes as a teenager, while I never had this problem with a TV.
My first computer was a TRS-80 Color Computer 2. Neon green screen with "black-ish" text, 32 col x 16 rows. Cursor was a rainbow flashing block. I'm still not certain whether someone with epilepsy couldn't be triggered into a seizure by that screen...
Now imagine being 10 years old, and having that in front of your face while coding in BASIC, glowing from a 19" TV mere inches in front of you...hehe. That was me!
I won't claim one way or the other to not have suffered damage of some sort - I'm really not sure.
Strangely, my mom always complained to me about "sitting to close to the TV" - but had no problem when I was in front of this thing for hours on end, typing away, etc.
You're misunderstanding interlacing. Interlacing was a way to still keep 50Hz (or 60Hz in some parts of the world) while having twice as many rows. It didn't give you a higher refresh rate than that.
No, but the difference in scanning pattern does provide a quite stark perceptual difference between 15KHz interlaced and 31KHz progressive at 60Hz. The scanning of fields seems to provide a higher chance that field 1's bottom lines won't have disappeared by the time the monitor is scanning field 2's bottom lines. Of course, it's largely dependent on a monitor's specific phosphor persistence, and why high-persistence monitors were so common in the earlier days of personal computing.
Not necessarily lasting physical damage, but flickering CRTs, or for that matter flickering fluorescent or LED lights can cause headaches, nausea, ...
I've certainly noticed it myself, using 75 Hz CRTs made me feel tired after a few hours, unlike 85 Hz.
> In 1989, my colleagues and I compared fluorescent lighting that flickered 100 times a second with lights that appeared the same but didn’t flicker. We found that office workers were half as likely on average to experience headaches under the non-flickering lights.
I always worry about what those jarringly bright LED brake lights with a low refresh rate (the ones that leave highly distracting dotted red trails across your field of vision when you move your eyes) are doing to my eyes and everyone else's.
One thing I don't miss from CRT monitors from the 90s.