Preserving food, less fighting for food, less roaming to hunt and gather. More stable sense of community. More children. Preserving food, less fighting for food, less roaming to hunt and gather. More stable sense of community. More children.
Contrast sensitivity is the ability of an imaging process to produce an image of objects or tissues in the body that have relatively small physical differences or inherent contrast. The contrast that is to be imaged is in the form of some specific physical characteristic.
This is where the photoreceptors are located. If you think of the eye as a camera, the retina would be the film. The retina also contains the nerves that tell the brain what the photoreceptors are seeing.. There are two types of photoreceptors involved in sight: rods and cones.