LEONARDO DA VINCI 1452-1519

Leonardo da VINCI Vinci, 1452–Amboise, 1519 Optics: Studies on the Physiology of the Eye Left-hand page: Experiments with the Crystalline Lens Right-hand page: Binocular Vision Black chalk, pen and brown ink on paper About 1508–1509 Leonardo carefully studied the anatomical structure of the eye and experimented with the theory of a double inversion that would correct the image reversed by the crystalline lens. For the experiment recorded in Manuscript D, he used a glass sphere filled with water to reproduce the lens. Paris, Institut de France, Manuscript D, fol. 3v–4r Leonardo da VINCI Vinci, 1452–Amboise, 1519 Optics Left-hand page: Shadows Projected onto a Screen Right-hand page: Gradations of Penumbra Pen and brown ink on paper About 1490–1491 On the left-hand page, Leonardo studies the shapes of shadows projected onto a screen by objects illuminated by light sources of different shapes. On the right-hand page, he analyses the gradations from penumbra to pure shade produced by two opaque spheres illuminated by two spherical light sources. Institut de France, Paris, Manuscript C, fol. 18v–19r 0 83 0 84 Ancient scholars developed two conflicting theories of vision. According to the emission theory, rays of light were emitted by the eyes themselves, while the intromission theory claimed that light entered the eye after being reflected from other objects. The latter theory was supported by the medieval Arab scientist Alhazen (965–1040), on whose findings Leonardo based his own optical experiments.