Please read my post before commenting.
I’ve heard the elbow thing and the “what do you see behind you” thing a hundred times.
My thought process is that the optic nerve is essentially an HDMI cable. Whether it is connected to a computer that is turned off (a closed eye, if you will) or just completely disconnected (suppose you are missing an eye or something), the signal it sends to the monitor is the same: nothing.
The “monitor”, the visual cortex, as far as I understand, just constantly processes what the optic nerve sends. So if blind people don’t lack a visual cortex, and the signal that cortex receives from the optic nerve is identical to that of a regular person seeing zero light (assume closing your eyes means 0 light, disregarding light seeping through eyelids and whatnot), how can you say that blind people see nothing while we see black?
In: Biology
> the signal that cortex receives from the optic nerve is identical to that of a regular person seeing zero light
Yes, but the *psychological interpretation* of that signal differs from person to person.
A sighted person *expects* to see things at least once in awhile, and thus their brain is geared to pay attention to the optic nerve signal. An environment of total darkness registers as “seeing black”.
A blind person (especially if they’ve been blind for a long time) has no expectation of ever seeing things, so their brain is geared to ignore the optic nerve. This registers as “seeing nothing”.
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