As I mentioned earlier, quite a few times, the amount of time involved in step #2 would generate a significant and noticeable time lag and energy drain ( if at all possible to begin with).
There appears no time lag and there are no empirical based studies using the scientific method dealing with this particular issue that I can find.
1.
Eyes of higher animals have a
fovea - a central, small area of the retina where we do our primary seeing. It feeds about half of all the nerves. Everything else we see with peripheral vision. You'll notice, if you try to use your peripheral vision to do anything other than catch movement, it is actually rather difficult, compared to seeing with your fovea.
So, when looking at the stars, you indeed see (and process) only a very small area of them - the rest is in far less detail.
Try looking directly at
this word on the page, now try to read the rest of the sentence - or any other part of the page - without moving your eyes from that word. It takes a very noticeable length of time to get it. (See how fast you can read it out loud, and you'll get the idea.)
2.
While you're busy concentrating on everything in your fovea, your brain is helping you out, by retaining imagery that's in your peripheral vision. Try this tonight, looking out at the stars. As you move your fovea around, just slightly, you will detect that the stars in your peripheral vision will shift and wobble. They'll fade out, then jump back in. This is your brain updating the "helpful" image with new information as the slow peripheral detectors notice it. (It's also partly that your retinal detectors are getting "tired", and get less and less stimulated over time. This is why we have saccades, so our detectors get refreshed.)
3.
Your eyes are constantly moving, even when you are staring directly at something. These movements are called saccades. They take only about 60th of a second or so, but your brain is completely oblivious to them. They occur faster than the brain's processing power.
4.
You blink all the time - more than you think you do. These blinks are also quite short - on the order of a 60th of a second. They also fall below the brain's threshold of processing.
These are all signs that you do take a non-zero time to process information. Some quite fast, some quite slow. Your brain takes a large fraction of milliseconds to process things, and that's still faster than many of the things your vision-brain does together.
This delay does not normally interfere with your vision in daily life - and one of the primary reasons for that is that your brain is going to a lot of effort for you to not see any lag.
But you can "hack" your vision. You can try various experiments (such as the ones above) to show, beyond any doubt, that
a] your
eyes take time to register things (persistence of vision, about 1/10th of a second)
b] your
brain can look at (and process)
only so much information at a time
c] there is a detectable delay between capturing an image and processing it, and finally, that
d] a
large part of the your brain's processing is devoted to making you
think you are seeing an accurate rendition of reality (both in static images
and over time).
There are many, many books on the subject.
