First of all, the surgeon, viewing through a surgical microscope sees operative site in stereo. The assistant (PA, Resident, Fellow) viewing the procedure through a stereo side observer sees the operative site in 2D not stereoscopic. The only way for an assistant to have a stereopsis view the same as the surgeon’s is a face to face set with the surgical microscope.
Therefore, all the clinicians have to view are 2D HD monitors. The Residents and Fellows in training will not operate with one eye, why should they train essentially with “one eye”.