Though man has begun to study vision at beginning of Christian era, many branches of vision, such as bio-vision, its sense process etc, were still puzzled.

• 虽然，人类从公元初就开始了对视觉的研究，但是，人类对视觉的许多分支，如生物视觉、视觉信息的感知过程等，还是充满着诸多的迷惑和不解。