Certain neurons seem to be wired to detect certain angles, lines, edges, and movements. for example, we can quickly detect the features of a human face and interpret the expression on that face. the nerve cells that respond to these specific features are called:

Visual information are captured in the retina and transduced to the occipital cortex via the optic nerve, optic tract, optic chiasm, and optic radiation respectively. There are neurons that respond to shape, angle, movement, and fine details. These neurons are called feature detectors and they respond to the details of the visual stimuli and relay this information to other cortical areas.

Yes he thought they should be left to chance why, because he thought that was the best thing to do