This is where vision happens in your brain. It takes all the signals from the rods and cones and positional muscles of the eye, and paints a picture for your higher order brain functions to look at. It computes depth perception and is important in hand-eye coordination.
"And they came to Bethsaida. And some people brought to him a blind man and begged him to touch him. And he took the blind man by the hand and led him out of the village, and when he had spit on his eyes and laid his hands on him, he asked him, "Do you see anything?" And he looked up and said, “I see people, but they look like trees, walking.” Then Jesus laid his hands on his eyes again; and he opened his eyes, his sight was restored, and he saw everything clearly."— Mark 8:22-25, ESV