http://en.wikipedia.org/wiki/Visual_acuity (Necessary for calculating distance modifiers.)
http://en.wikipedia.org/wiki/Optical_resolution (May be interesting for constructing modifiers for Optical devices used for spotting.)
I am also searching for material that at least approximates scientific validity for how camouflage works on brain and retina, and how to reproduce these effects in the limited frame that can be made up in the RV engine.
This new approach would have its own problems, for example, Units should not turn transparent when skylining themselves to the player. How to handle lightsources as well as muzzleflash and muzzlesmoke for detection would also be need to be resolved.