I suspect this will only be of interest to a few of you, but if you work with photography or optics at all, it’s useful to correlate the performance of constructed optical systems with how the human eye works. What is the maximum resolution of the eye?
The following two links go over how human optical performance is measured, and the limitations in human optics. In a few ways, human eyes are superior to any CCD or CMOS sensor ever created; even in the presence of a very bright light source your eyes can detect a lot of detail in dark areas of the image. On the other hand, even a very basic consumer camera has a larger effective aperture than your eyes. It’s a very interesting read, and gives plenty of detail for jumping off into biology if you’re curious.