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The ''Book of Optics'' ((アラビア語:''Kitāb al-Manāẓir'') (كتاب المناظر); Latin: ''De Aspectibus'' or ''Perspectiva''; Italian: ''Deli Aspecti'') is a seven-volume treatise on optics and other fields of study composed by the medieval Arab scholar Ibn al-Haytham, known in the West as Alhazen (965– c. 1040 AD). The ''Book of Optics'' presented experimentally founded arguments against the widely held extramission theory of vision (as held by Euclid in his ''Optica'') and in favor of intromission theory, as supported by thinkers such as Aristotle, the now accepted model that vision takes place by light entering the eye.〔D. C. Lindberg (1976), ''Theories of Vision from al-Kindi to Kepler'', Chicago, Univ. of Chicago Press ISBN 0-226-48234-0〕 〔Nader El-Bizri, 'A Philosophical Perspective on Alhazen's Optics', ''Arabic Sciences and Philosophy'' 15 (2005), 189–218〕 Alhazen's work extensively affected the development of optics in Europe between 1260 and 1650. ==Vision theory== Before the writing of the ''Book of Optics'' there were two types of theories of vision that were held in contention. One was the extramission or emission theory. This theory was presented by the mathematicians Euclid〔(Euclid's Optics )〕 and Ptolemy〔 *(Smith, A. Mark (1988) "Ptolemy, Optics" Isis Vol. 79, No. 2 (Jun., 1988), pp. 188-207, via JSTOR ) *( Smith, A. Mark (1996) Ptolemy's Theory of Visual Perception: An English Translation of the "Optics" with Introduction and Commentary Transactions of the American Philosophical Society 86(2) (1996) via JSTOR ) *(Smith, A. Mark (1999) Ptolemy and the Foundations of Ancient Mathematical Optics: A Source Based Guided Study Transactions of the American Philosophical Society New Series, 89(3) (1999) via JSTOR )〕 and asserted that certain forms of radiation are emitted from the eyes conically onto the object which is being seen. The striking of the rays on the object allow the viewer to perceive things such as the color, shape, and size of the object. The opposing theory was the intromission theory held by the followers of Aristotle and Galen which held that agents were transmitted to the eye from either the object or its surroundings and caused perception. Al-Haytham held the intromission theory of vision, offering many reasons against the extramission theory. He drew on the fact that eyes can be harmed and damaged by looking at very bright lights, such as the sun, directly and for a prolonged period of time, showing that light has an effect on the eye, not the other way around.〔 He also claimed the high improbability of the ability of the eye to fill up the entire area of space and the stars the instant the eyelids are opened as an observer looks up into the sky.〔(【引用サイトリンク】title=Ibn Al-Haytham, Abū )〕 Using the intromission theory as a foundation, al-Haytham formed his own theory that an object being viewed emits rays of light from every point on the object which travel to the viewer's eye. According to his theory, the object being viewed is not considered as a whole object, but a compilation of an infinite amount of points that together compose the entirety of the object from which the rays of light are projected. 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「Book of Optics」の詳細全文を読む スポンサード リンク
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