Is it the eye that actually determines what we see or the brain that interprets it for us or tries to process it?
Is it the eye that actually determines what we see or the brain that interprets it for us or tries to process it? The eyes can be open but, lack the ability to see even when observing things. Are eyes really what people use to see or just to look?
Vision is done by the brain, specifically that part at the very back of the head called the occipital cortex.
Our eyes provide two optimized images that are broken down into "categories" of data which are transmitted to the occipital cortex. The data is then re-assembled by the brain into the most probable representation of what is "out there." Vision is not a passive thing where two "TV cameras" relay an image to the brain to recognize. Strange as it may sound, vision is an active process. We see what we expect to see based on past experience, emotions (fear, interest, desire etc.) and our physiological needs like hunger. The brain is continuously updating this input based on new and changing conditions and then projecting that model onto the real world.
Obviously, this projection is rather close to what is actually out there or we would be stepping in front of cars or off cliffs! But our ability to make sense of what the eyes see is a learned skill, much like learning a new language. If a child were raised with one eye permanently covered, that eye would never be able to "see" in any meaningful sense should the patch be removed as a teenager, or an older person.
J. Trevor Woodhams, MD - Chief of Surgery, Woodhams Eye Clinic