Well actually Fred's eyes (and brain) do control how far Fred "sees" as opposed to how much there is illuminated sufficiently to see.
The other day I was watching a REALLY good shortie on how readily our natural night vision is reduced (minutes). And how long it takes to recover (days). And this is a factor I am sure is a MAJOR encumbrance. So much so I am off to research medical reference journals a bit. Also light colour matters.
I did a lot of research on what enters the eyes and what we "see" when I was working with some military "ocular aiming devices" mfrs. I need a ruddy light meter now so I can fully explain this. But sometimes we really do not "see" the elephant in the room.