Young discovers astigmation and proves that accommodation is not due to changes in the length of the eye or in the curvature of the cornea. Young proposes three receptor theory of color vision. Ritter discovers ultraviolet light. Young discovers interference. 1804 Troxler describes loss of color in the periphery of the visual field.
Gall proposes concept of localization of mental functions in the cortex.
1808 French Academy refuses to admit Gall on grounds that the cortex has nothing to do with thinking. Young proposes transverse wave model of light. 1818 Vieth-Muller horopter. Wollaston explains homonymous hemianopia in terms of partial decussation at the chiasm. Niepce makes the first photograph.