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The visual system is the part of the central nervous system which gives organisms the ability to process visual detail, as well as enabling the formation of several non-image photo response functions. It detects and interprets information from visible light to build a representation of the surrounding environment. The visual system carries out a number of complex tasks, including the reception of light and the formation of monocular representations; the buildup of a nuclear binocular perception from a pair of two dimensional projections; the identification and categorization of visual objects; assessing distances to and between objects; and guiding body movements in relation to the objects seen. The psychological process of visual information is known as visual perception, a lack of which is called blindness. Non-image forming visual functions, independent of visual perception, include the pupillary light reflex (PLR) and circadian photoentrainment. ==Structure== This article mostly describes the visual system of mammals, humans in particular, although other "higher" animals have similar visual systems (see bird vision, vision in fish, mollusc eye, reptile vision). In the case of mammals (including humans), the visual system consists of: * The eye, especially the retina * The optic nerve * The optic chiasma * The optic tract * The lateral geniculate body * The optic radiation * The visual cortex * The visual association cortex. These are divided into anterior and posterior pathways. The anterior visual pathway refers to structures involved in vision before the lateral geniculate nucleus. The posterior visual pathway refers to structures after this point. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Visual system」の詳細全文を読む スポンサード リンク
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