While minimal access neuroendoscopic surgery is a rapidly growing field, adoption of new techniques is often hampered by a steep learning curve. One of the restrictions of endoscopic or endoscope-assisted surgery is the lack of binocular, or stereoscopic, vision. Monocular endoscopes and displays create a two-dimensional (2D) image which impairs depth perception and the ability to estimate size. Particularly in neurosurgery, where procedures are performed deep in the brain through long narrow corridors, impaired depth perception can be disastrous. Neuroendoscopic procedures, particularly transnasal skull-base procedures, are currently performed with 2D endoscopes that lack stereoscopic vision and depth of field as hown in Fig 3.1. In spite of the limitations of the 2D endoscope, neurosurgeons have been able to train their eyes, brain and hands to adapt to the lack of 3D vision. Nevertheless, it is likely that an effective high definition 3D endoscope would improve depth perception. This improvement may be particularly important for surgeons with limited 2D endoscopy experience.