When the information from the light leaves the retina, it goes to the brain. It travels along the optic chiasma until it reaches the optic cortex at the rear of the brain. The information is then processed to find out the shapes and colours of objects. From that and from memory, it can tell of what kind the object is. For example, it can somehow tell a tree from a house. The path on which this kind of information flows is called "ventral stream".