Anti-Realism “The image will be inverted, reduced in size, and real. Quite conveniently, the cornea-lens system produces an image of an object on the retinal surface... Fortunately, the image is a real image - formed by the actual convergence of light rays at a point in space. Vision is dependent upon the stimulation of nerve impulses by an incoming light rays. Only real images would be capable of producing such a stimulation. Finally, the reduction in the size of the image allows the entire image to "fit" on the retina. The fact that the image is inverted poses no problem. Our brain has become quite accustomed to this and properly interprets the signal as originating from a right-side-up object.”
- physicsclassroom
While the image my mind perceives will have the identical quantitative dimensions that a camera would have, there still seems to be some qualia attached to our vision. A camera appears to pass on colour to our brain rather than being the source of the colour itself. A colour-blind person would see different colours when looking at the same camera screen or photograph. However, we’d both agree on the objective spatial and proportional features. What gives?
It seems subjectively inconceivable that the sentient contents of my visual system could themselves be projected onto a screen no matter what brain-scanning technologies one might have in the future. Might an upshot of this be that the real image our eyes receive must somehow be converted into a virtual image in the brain? That is to say an image which “cannot be projected onto a screen because the rays never really converge”. Phosphenes are incongruous entities: “an impression of light that occurs without light entering the eye and is usually caused by stimulation of the retina (as by pressure on the eyeball when the lid is closed).” The apparent irreducible and internal nature of phosphenes makes it hard to imagine them ever being by some means transplanted onto an external screen. Another person can’t see exactly that which I observe in my mind’s eye.