Eye's optical system is composed of single lens and is capable of producing very sharp results, but if I use single lens (monocle) with my camera I'll get soft image.

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    \$\begingroup\$ It probably has something to do with the brain correcting the image, but I am not sure and I don't know the details. \$\endgroup\$ Commented Mar 6, 2014 at 17:02
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    \$\begingroup\$ Single lens systems are very bad at projecting onto a flat surface like a digital camera sensor. They are much better at projecting onto curved surfaces like the retina. As soon as affordable curved sensors are perfected expect some very low aberration lenses! \$\endgroup\$
    – Matt Grum
    Commented Mar 6, 2014 at 17:12
  • \$\begingroup\$ See also How does the human eye compare to modern cameras and lenses? \$\endgroup\$
    – mattdm
    Commented Mar 6, 2014 at 17:25
  • \$\begingroup\$ It is not a photography question, which IMHO is clearly reflected in the question not having received any upvotes so far @Andrew It is well suited for the biology.stackexchange.com community. \$\endgroup\$ Commented Mar 6, 2014 at 20:30

2 Answers 2


Two reasons: A camera objective (made up from many lenses) needs to focus on a plane, not an arc. And we dont see the image projected on the back of our eye ball. We build up the image from features extracted by many neurons with each their specialty. That's why we don't have to show reality to the eyes for us to see the same, we just need to construct something that "pings" the same neurons. Need not be the same. Which is kinda scary - can we really trust what we see? Nope, that's part of why accidents happen.

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    \$\begingroup\$ Much more reasons. But put bluntly, we see with our mind and not our eyes. That alone invalidates the old believe of humans only using a few percent of their brain's capacity. \$\endgroup\$ Commented Mar 6, 2014 at 20:27

Simply put, it does, our brain corrects for it. Among other things, you can't actually see where your optic nerve attaches to the retina and your visual acuity is actually much more center focused than even a cheap camera lens, but because your eyes refocus on the fly every time you change where you are focusing, you don't notice the changes or the lack of acuity.

We also have really crazy image stabilization built in to our brains as well because your eye moves around far more than you realize, and it jumps rather than generally moving smoothly. Try taking a video of your eye sometimes as you read a page or look around the room. You will probably be very surprised by what your eyes actually do.

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    \$\begingroup\$ Not to mention that great gaping hole that we automatically fill in with a combination of remembered and interpolated data, static data that are ignored until their background changes (anyone old enough to have floaters knows what I mean) and the whole HDR-in-live-view thing that's going on. Our vision is good, but that's almost in spite of our eyes. \$\endgroup\$
    – user2719
    Commented Mar 6, 2014 at 18:57
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    \$\begingroup\$ Yes, good point about the HDR thing. Most people would probably never guess that we actually have camera sensors now with higher dynamic range than the human eye, simply because they don't notice how insane our eye is at adjusting the iris on the fly. \$\endgroup\$
    – AJ Henderson
    Commented Mar 6, 2014 at 18:59
  • \$\begingroup\$ My brother experienced this first hand. He got injured and tore his retina in one eye, so he had a big black spot in the middle of his vision. Over a couple of months, the spot slowly shrank until it disappeared. No, the retina didn't repair itself, he still sees the spot when he closes his good eye. The brain just compensates and learns to fill in the blanks. \$\endgroup\$
    – Robin
    Commented Mar 13, 2014 at 15:00

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