Answering the Unanswerable: What is the Resolution of the Human Eye?

What is the resolution of the human eye? You might think it’s a straight forward question with a straight forward answer. We have a certain number of photon collecting cells in our retina much like an image sensor right? So we should be able to pull a ‘megapixel’ count of sorts out of there.

Well, actually, it’s not nearly that simple. And in the video above, video blogger Michael Stevens (aka. Vsauce) explains why, before ultimately answering the question anyway.

The reason this question doesn’t have a straight forward answer is that our eyes don’t see the same way a video camera does. We don’t see in fully formed snapshots with even resolution throughout. In fact, each ‘frame’ or glance our eyes pick up is rather crappy; an image that “would hardly even acceptable on a broken TV screen,” as Stevens puts it.

As this XKCD comic on the visual field (click image for high-res) outlines beautifully: we have blind spots, eyeball ‘goop’, and a significant drop off in our ability to see color and detail as you move away from the exact spot we’re staring at.


The truth is, high-resolution sight as it were only actually occurs in the very middle of your vision, a tiny circle that extends two degrees from center and is detected by the high-res portion of your eye called the Fovea. Everything else blurs out and is filled in by your brain as your eyes move around and pull in a constant stream of visual information.

So… knowing all this, is it even possible to answer the question in the title? The answer, as with so many things in this world, is ‘sort of’ — and Stevens does eventually get to that answer (there are actually two answers) at the end of this fascinating video.

To find out those answers and much more from Stevens as he dives into the fascinating subject of human vision, check out the video at the top and reference the video description for links to all of Stevens’ source material.

(via Laughing Squid)

  • Sky

    The thing with polarization is in general quite weird. I know many people are unable to see it, even if they are given best possible instructions and try to do it under oversight with strongly polarized light sources. I guess I’m somewhere in the average – I can see polarization of computer screen, but often can’t see one on a sky or reflective surfaces – I got a friend (graphic designer) who can see these too.

    Training though is certainly a factor – I remember seeing for the first time when I read about it somewhere as a very, very faint yellow, now I can spot it quite easily from polarized light sources. So if you can’t see it – don’t give up. Few attempts in different lighting and you might see it eventually :)

  • Mike

    I did the polarization thing and saw it but now I can’t walk straight and keep bumping into my mother-in-law

    send help!

  • Scott M.

    Excellent video!

  • Ralph Hightower

    Interesting. Informative.

  • George Williams

    Resolution – ever noticed how you can resolve linear objects (power lines, guy wires) from miles away which implies a resolution much finer than the fraction of an arc-minute mentioned in the video? I have to do the experiment to see if my camera and lens set to my eye’s focal length (say, 40 or 50mm) can perform as well.

  • Anonymoused

    Can somebody please just write his short answer? Is that too much to ask from an article? I’ve no sound at work, and even at home I don’t want to watch through a whole video just to find out a simple answer.

  • hghg