Is using a large TV as a computer display harmful in the long term?
 

Saw a guy once that had a TV on the wall right behind his desk. He was using it as a computer display. Was he probably harming his health by doing that?

Should the TV be further from the eyes and then it would be ok?

Would a special TV be healthier?

Would a large computer display not make a good TV? Not watching TV that much myself but just saying.

A TV uses the same screen technology as a computer monitor - how far you sit from it is a personal thing, the same with contrast & brightness. :)

I'm sure spending a lot of time 1-2 feet from a display or book like we all do is harmful. Something to do with the eye lenses retaining something from the near-focus shape. Then a huge display at the opposite wall of a room is possibly more ergonomic? Never seen this recommended anywhere.

The time of cathode ray cannons is over, so I assume you are refering to eyesight?
I think it's good to not sit too close to the monitor; have mine at 80cm.
But in the end you have to change the distance regularly so your eyes don't get used & locked into one distance, if you spend many hours on end at a computer. It's a muscle like any other and needs exercise.

Yes we are only talking about current displays, and even paper reading is potentially harmful as illiterate societies have shown: almost no one develops eyesight issues even though the genetics for them may be present. But then, why don't ergonomics experts recommend the largest display you can afford at the largest distance you have space for?

I went from fixing tvs to Electronics & pcs. The older the tv, the worse it was. I found contrast was a factor, because there's a limit to the contrast the eye will accept.That causes eye strain. Nothing else matters imho.
That said, the bigger the Monitor/tv, the further away I'd put it. Bigger screens put out more energy, and you want less energy.

The size of a normal(ish) desk, is fine for a monitor upto about 19", above that & you would benefit by moving back further from it.

I can't understand these people that have 2x 24" monitors on their desks, surely they can't take in everything that's on both screens, & would have to move their heads a lot....

My preference is for a smaller screen, & I use an 8" XGA on occasion, with my RPi3A+, & a 11.6" WXGA with my RPi3B+, or a 12" XGA sometimes.

(I still keep a 15" XGA around for use with my main desktop sometimes too, although I did buy a 24", but find I'm sitting too close to it most of the time.)

I have a computer (Intel NUC) attached to my main TV, for multiple uses, and it's ok for some things like media consumption, but not so great for most computer use. The text is just too small for reading at a distance of tens of feet. The definition is high enough, but it's just so small that it's very hard to read. I suppose I could reduce the resolution to make the text bigger, but it would affect other things adversely. I have the terminal text big enough to read, but the GUIs are difficult.

I find having too much of my eyes' field of view occupied by a display uncomfortable. Yet one is often forced to do that by high resolution displays - you can't just put computer displays too far like you do with TV's.

Increase the dpi.
You can experiment with different dpi settings without changing anything.
man startx

Just anecdotally: I never experienced any problems using a 43" 4K TV as the sole monitor on my workstation for a while - I did eventually go back to 'normal monitors' but it really wasn't any different (my eyes don't feel any more or less tired/strained/etc, my neck isn't more or less strained, etc). I did sit a bit 'further back' with the big display (I normally sit around 3ft back anyways, but with that it was probably more like 4), but it wasn't unusable or anything. It did get annoying playing window tetris vs being able to just maximize things to individual monitors, and that was part of why I switched back to a more normal multi-monitor setup. Power-wise the newer displays are so efficient that it wasn't bothersome in terms of heat - I think the set uses like 40W. By contrast, I still remember the original 30" Apple display (and the various non-Apple clones from Gateway, HP, etc) and those had a bit of the 'sun lamp' effect - a lot of those displays were also taking in 200-300W/ea (!) for their backlighting (and their cabinets would get quite warm in operation). I'm glad to be 'past' the CFL backlights and big CRTs in terms of power/heat output.

All of that said, I'm not sure I would want to go much bigger than 40-43" - I've helped setup some simulator stuff in the past, using 60-70" projection displays, and working on those jumbo displays 'close up' is annoying. At 12ft they're fine, but that seems a little silly for an office/desktop environment.

Harming his health? Probably not but such an arrangement would not be very ergonomic. I would caution against using that setup that for an extended time. My neck hurts just thinking about using a monitor that's too far above my desktop.

Cheers...

Was using a laptop at desk height for a while and ended up with a slightly bad posture, a tendency to hunch. Took a couple of months to correct this, with squats at the gym. Now the laptop is only used with an external display and keyboard and that display is height-adjusted so the center is at eye height.

That's not what I said. Keeping your eyes focused at any unchanging distance for a long time is "harmful". The only thing that will prevent you from requiring glasses evtl. is eye excercise - meaning, move those eye muscles, meaning: change the distance all the time. Some people recommend taking your eyes off the screen for 5min every 20min or so.
I would add to that changing your seat/keyboard/screen arrangement every now and then.

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