My eyes are about 28-30 inches away, and thats about the best I can do with the current desks we have. The two screens are already pushed against the cubicle walls, and the desks don't offer keyboard trays. I did have my desk lowered to ensure better ergonomics for typing, and have the monitors on stands.

We are moving into a new buildout with mo space, so I should be able to arrange the desk better to take advantage of the full space of both monitors without having to turn my head so much. At home I usually sit around 40 inches away from the 27 inch display.