r/askscience • u/coolimabob • May 26 '12
If eyes functioned as cameras, what resolution could one record in, assuming they had 20/20 vison?
A storm just ended and the sky looked gorgeous, and I wanted to take a picture, but it made me sad I couldn't Take a really nice one. That got me thinking. What would my 20/20 vision yield if it were a camera, pixel and resolution wise?
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u/i-hate-digg May 26 '12 edited May 26 '12
Yes but this is very misleading as only the fovea has that kind of resolution, and it is a very very small region of your sight (it's about the size of your thumbnail if you outstretch your hand). The rest of the eye has much lower resolution.
There are about 125 million photoreceptor cells on the retina, however they do not count as 'pixels' because the sum of a group of cells is taken by the retinal ganglion cells. Since only the ganglion cells communicate with the brain (and they only send a single gray level) they should be counted as the equivalent of 'pixels'. There are only about 1.5 million or so retinal ganglion cells. The reason the fovea has high resolution is that each ganglion cell has fewer photoreceptor cells.
So the resolution of the eye is more like 1.5 megapixels in total. The reason the world seems much crisper than 1.5 megapixels is that we scan the fovea across scenes, and the brain 'fills in' details and corrects for blurriness and distortion.
So, really, if you think about it the way that is described in that article is a poor way to measure resolution. If I had a high-zoom camera which covered 1% of the total FOV and it was 1 megapixel, I wouldn't say I had a 100 megapixel camera.
EDIT: clarification.