视觉是一种生物性的机能活动,大部分的生物藉由视觉系统的作用,与其他生理机能作用的共同协调以作为维持生存的基本要素。原则上,视觉能力是一种行为能力的特征与肢体控制的基础元素,一旦失去,在没有辅助的状态下,则会造成生存的威胁。 视觉系统的动作与自然界的条件有很密切的关联。除了生理性的器质构造外,必须经由光的运动才能引起作用。在 Visual is a biological activity, most of which are coordinated by other physiological functions through the function of the visual system as basic elements of survival. In principle, visual acuity is a characteristic element of behavior ability and the basic element of limb control. Once it is lost, it will threaten survival if it is not supported. The movements of the visual system are closely related to the conditions in nature. In addition to the physiological texture of the device, it must be through the movement of light to cause effect. in