The Theory of Vision


THE view that the stimulation of the cones of the retina is indirect and takes place through the photo-chemical decomposition of the visual purple by light seems to be proved and a fact. How can the colourless transparent cones be directly stimulated by light? How does this direct stimulation agree with the laws of photo-chemistry? According to Grotthus's law, no effect can be produced by light unless it is absorbed.

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