In addition to the oracle's advice (can't vouch for Richard Gray, because of lack of experience and general skepticism about such things), I'd advise making sure your visual center is no more than horizontal, preferably a bit lower. Bending your head back to look up at a screen can bring on unexpected nerve pinching.
Before the days of personal computers, I had the screen of my terminal mounted on a shelf where I looked slightly up at it. When I bent over to sign something, I often experienced numbness in my arm. A series of unpleasant tests, including a series of shocks to test neural conductance, failed to uncover the problem, so I was hung with my head in a sling as therapy to no avail. I came across an IBM tech paper that recommended placing monitors so that viewing was slightly below horizontal. The nerve problem has never reoccured after relocating the monitor, and that was nearly 40 years ago.
db
Before the days of personal computers, I had the screen of my terminal mounted on a shelf where I looked slightly up at it. When I bent over to sign something, I often experienced numbness in my arm. A series of unpleasant tests, including a series of shocks to test neural conductance, failed to uncover the problem, so I was hung with my head in a sling as therapy to no avail. I came across an IBM tech paper that recommended placing monitors so that viewing was slightly below horizontal. The nerve problem has never reoccured after relocating the monitor, and that was nearly 40 years ago.
db