Our resolution varies across our FOV, but is best measured in the center of vision. (Ironically, we can potentially see smaller objects away from the center, but... biology is analog, not digital, and weird.)
Focal length is merely the conversion factor from physical resolution at the receiver side to angular resolution in the real world. It varies, but not by much, eye to eye, with vision aids (glasses, etc.), and (very trivially) with distance to the object. So, it's basically a constant.
I’m pretty sure you just confirmed that focal length varies. So I stand by my statement. Our rods and cones enable us to see great detail and yes, it’s more concentrated in the center of field of view, but if we’re talking pixels… 567MP is what people claim. I know it’s a lot higher. Pilots are able to spot specks at 4nm. Astronauts can see objects that are just a speck at 50nm. Our actual eye resolution is insane when paired with the right focal length.
I wrote a longer post, but I'll keep it short: you can't compare 100 small res cameras + an inference engine that combines the samples together (our brain with low res foveal samples) on the same metrics you'd judge a single camera with 100x more res. They simply see, resolve and process things differently.
To stick with your example: the pilots that "see" aircraft at 4 nautical miles don't "see" them because their foveas have super human pixel density. But because high-contrast very low res foveal samples + contextual inference + motion + time, give more time to the brain to infer the presence of the aircraft. But if you had the ability to stop the motion and image the very same aircraft would "disappear".
I confirmed it varies trivially. That means it effectively doesn't vary.
Your statement about resolution being infinite is laughably wrong. I assume you don't even understand what "infinite" means.
You wrote two sentences that are both wrong.
Also, your understanding of resolution is lacking. Our eyes aren't uniformly covered at all. The MP amount you claim is "virtual", for want of a better word. It's like taking an SD (480p) video for one second, combining it with AI, and extrapolating a 500MP single photo. It's very like that, in practice.
Resolution allows you to pick up different image features, it's not infinite. A zebra pattern will eventually merge into a solid gray color upon shrinking, that's your actual resolution limit. But a single dot or a line surrounded by enough background will still be visible way below this limit because it has enough energy difference to activate a photoreceptor, even though you won't be able to tell its true size or thickness.
I don't think it's actually infinit, but it's probably very high! We do have little receptors (cones) in our eyes (retina) that react chemically to light. So the density is the resolution (and different cone types react to different wavelengths, which is why some people are coloured blind, for example)!
- we are all colorblind, as we only see a very small part of the light spectrum
- there are no two individuals that perceive colors in the same way in the world as the receptor distribution changes by person to person (actually, even day by day on a single-individual basis)
