Right, but it seems like the eyes can plug straight to the unconscious parts of the brain more easily that a Rube Goldberg connection via messages to the heart

Right, but it seems like the eyes can plug straight to the unconscious parts of the brain more easily that a Rube Goldberg connection via messages to the heart and back again. Like, whatever connection there is from the eyes to the heart is going to go via the spinal cord anyway. It could stop off and tell the brainstem on the way down.