NATS 1870 Chapter Notes - Chapter 15: Retina Horizontal Cell, Scotopic Vision, Visual Phototransduction
21 Sep 2017
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Document Summary
Physiology of the human colour vision system iii. Spectral, intrinsic, and population-weighted sensitivities to light. Intrinsic sensitivity: minimum number of photons required to activate a single photoreceptor, such that the fewer the photons are needed, the higher the sensitivity of the photoreceptor. The three types of cones are not in equal. The problem of univariance (or, why we need numbers in the retina. several types of photoreceptors) Trichromacy (distinguishing lights as a unique set of 3 ring rates) Metamers as examples of limitations of trichromacy. Spectral sensitivity: range of wavelengths of light which a photoreceptor is able to absorb. Note: this graph shows the range of wavelengths only (x-axis), that a single cone of each type can absorb. Majority of the cones are m & l types. S-cones are the minority of cones (6%), and they are located on the outer regions of the fovea.
