Quote - The problem with photo-based textures is that they are comprised of pixels. This is not the fault of the CG camera.

If you looked at a digital photo very closely with the human eye, quality would still erode.

Quote - Paloth,

I think you misunderstand. Kawecki is not talking about the texture, he is talking about the fact that the human eye "auto-adjusts", for lack of a better term.

Is not the problem due the texture is made of pixels or the human eye adjusts.
In renderings the pixels are stretched vertically, more near the camera more stretched and the stretching increase is very un-linear.
If you increase the number of pixels they still continue to be stretched and look as dashes.
With human eyes this never happens, if you look at a grainy material with round grains, the grains remain round no matter how near we look. The only thing that change is that grains became bigger or smaller, but always round.

Quote - Not that any of this matters, but the human eye does not change focal length. It changes the focal plane, providing a choice between near or far objects being in focus.

There's no way to change the focal plane, there are no muscles in the back of the eye. Also would be easy for a person with short vision with some muscle exercises to achieve normal vision.
If there is no way to change the focal plane and the front of the eye doesn't move to change the focal length then the only remaining possible way to change the focus is to change the refraction index of the liquid inside the eye. Perhaps this really happens.....

Stupidity also evolves!