Page 23 - Black Range Naturalist, Vol. 1, No. 2

extra senses, the sensitivity to pheromones and the sensitivity to infrared light, involve whole organs that we don’t have.
quantum of light by a pigment molecule in a photoreceptor cell, just as it is in all other vertebrates. Virtually all living
Snake eyes are very similar to ours: lenses, retinas the whole bit. However, the snake eye has far fewer receptors and is not as good an optical device as the human eye. Being blinded would be a death sentence for almost any wild vertebrate. Diamondbacks included, probably, but Diamondbacks also depend heavily on other senses. Nonetheless, they behave as if vision is their primary window to the external world just as it is for most vertebrates. The primary event in snake vision is the absorption of a
things respond in some way to light but vertebrate photoreceptor cells are uniquely sensitive. Their “visual” pigments are members of a very large family of membrane proteins some which go back to when life was still in the one cell stage. Light and life have been intertwined almost from the beginning and visual pigments started very early. While some kind of absorption event is a necessary first step, vision is far more than the detection of light quanta. Instead, we should think of vision in terms
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