Hello I had asked a similar question a few months ago. My question was what is the recommended viewing distance for computer screens larger than 17". There is a lot of informaiton in there and you might be able to find an answer to your question. It can be found under the general discussion tab. Sandra
For an individual, distance from the monitor is as far away as possible while still being able to see smaller text.
I could see where this would be a challenge for a group, but as a suggestion, maybe you could have someone with 20/20 sit in your room with the same lighting and monitors that you’ll use, and see how far back the monitor is, using this guideline. Then you should have a depth measurement for your monitors that will also allow for closer monitor distances. Flexibility is a good thing.
Oh, and on the height, your subjects should have a slight down angle while looking at the monitor. You’ll have to do some calculating on the height range that you’ll want to use. For example, you could assume a minimum of 5 ft and a max of 6’4". But the measurement is really from the chair cushion to the eyes, with the chair in its lowest and highest positions. In all instances of the range, you should calculate that the angle from the eyes to the monitor is no greater than 90 degrees (looking straight ahead) and, again, preferrably a slight down angle.
If that warrants more explanation, I could provide a drawing.