Conventional ergonomics guides suggest aligning the top of the monitor to where the operator looks at straight on. It seems doubtful that that still applies to today's 24" and 30" and larger displays.
What was the reasoning behind that rule? What's the correct way to position a huge display according to current research?
Would anyone have a reference to research confirming the "2/3 up" rule?
Actually, the rule of thumb is to align your eyes (straight ahead) to about 3/4 up the height of viewable area of the screen. That is, about 1/4 of the screen is above eye-level, the rest is below and this should apply to any reasonable screen size.
Beyond that rule of thumb, the bottom of the screen should not be more than 60 degrees below the straight ahead horizontal viewing angle.
Here's what OSHA thinks:
- The top of the monitor should be at or slightly below eye level. The center of the computer monitor should normally be located 15 to 20 degrees below horizontal eye level (Figure 6).
- The entire visual area of the display screen should be located so the downward viewing angle is never greater than 60 degrees when you are in any of the four reference postures. In the reclining posture the straight forward line of sight will not be parallel with the floor, which may increase the downward viewing angle. Using very large monitors also may increase the angle.
I'll discuss the specific recommendations below, but let me start with the basis for them.
Do the recommendations need to be updated?
The question in this thread was recently re-asked (and marked as a duplicate). The reason was that the information here, and elsewhere, is old ("Has the science changed?"; is the underlying research still current?). Even in this question, the applicability of the research is questioned due to the growing size of monitors ("It seems doubtful that that still applies to today's 24" and 30" and larger displays"). These concerns are understandable given that the OSHA advice cited in one answer shows what looks like 14" CRTs from the early 1980s.
Basis for Current Recommendations
The OSHA recommendations were based on extensive research focused on human physiology. Humans are a few inches taller, on average, than we were centuries ago (thought to be mainly due to diet and medicine), but we have not evolved in the last few decades to adapt to growing monitors. The research behind workspace ergonomics still applies.
How well do the guidelines apply to the enormous monitors of today?
You can answer that with basic trigonometry. The OSHA guidelines discuss an optimum where the screen occupies a visual angle of roughly 30 degrees (top of the screen slightly below straight ahead and the center of the screen down 15 to 20 degrees from straight ahead). The rule of thumb for monitor distance is arm's length (about 28-30"). That gives you a total screen height of roughly 16", equivalent to a 32" monitor in a 16:9 format.
The OSHA guidelines discuss an upper limit where the entire screen fits in a 60 degree visual angle (which would require a little head movement to view top to bottom). A screen that size would be viewed from farther away, and the guidelines discuss a maximum distance of 40". That equates to a screen nearly 6 feet high, which would be a 12 foot 16:9 monitor.
If your problem is that your monitor is larger than 12 feet diagonally, you can probably afford regular chiropractic care and good glasses, and you will have the satisfaction of knowing that your monitor makes other people drool.
I personally have followed all of the standard advice, most of it listed above, but what was the ultimate solution was paying attention to if I slouch or not and correcting it.
The algorithm was: If I am slouching, even just a little bit, then I raise the monitor and repeat. There's a subtle but important difference than following suit to standards: I want the monitor height to not only be proper for when I sit straight, but I want it to promote me to sit straight.
The end results were my 22" monitors were positioned so my eye-level, while sitting straight, was about 1/3rd the way down the screen. The top of the screens were well above eye-level. Before, when the top of the screens matched my eye-level, I was still slouching; They were not high enough.
Now that I am done, the monitors feel very high off my desk. People make fun of how high they are.
It created another problem: I want to use arms to hold the monitors, instead of risers which take up all my desk room, and I have not been able to find any inexpensive ones that raise this high. The final height is about 11" off my desk. But, be aware that my desk surface is the level of my keyboard; I have no keyboard tray. My seat is fixed at a height which makes this ergonomically proper.
Hope this bit of personal experience helps.
I have three 20" LCD's left to right no gaps between the bezels. I find looking left or right more than 1/2 of those outer screen gives me a pain in my neck. For instance I often move the browser to the left screen (using nvidia hotkeys I setup CTRL-1,2,or3) to read an article or documentation. If I have to stay on that page more than about 30seconds my neck starts to have pain. Maybe it's because I sit about 18" away from the main screen. But I think there is a limit to how far you can reasonable turn your head left or right for a period of time. So what I try to do is have the browser use the right 1/2 of the left monitor so I don't have so far to turn.
I'm waiting for the 30" LCD's to come down as I think a single 30" with a decent windows manager will do just as well. Hope this was helpful. Although it was not scientific, just my own experience.