Human and Animal Vision

It turns out that humans are highly anthropocentric in how we conceive of vision. The measures that we use tend to be areas where problems in human vision arise: focusing at distant and close range, seeing at night, depth perception, field of vision, and colorblindness. We don’t factor in things that most humans can do easily, such as recognize patterns, and we also don’t think about things we can’t do at all, such as recognize the source of diffuse light.

Here is a list of factors that vision entails (which may not be complete):

Ability to detect light (this is the core function of vision)

Ability to locate the source of diffuse light (polarization)

Ability to see in low light

Ability to see in bright light

Sensitivity to changes in contrast

Ability to see colors

Range of color vision

Ability to distinguish hues within a narrow band of color

Depth perception

Detection of movement

Ability to see stationary objects

Field of vision (including ability to see up and down as well as on a 360 degree plane)

Focusing ability (including speed of focus on near and far objects)

Ability to detect images at great distances

Clarity of vision at far and close range (accommodation)

Ability to detect shapes, both solid and outline

Ability to recognize patterns

Rapidity of image formation (analogous to frames per second in a camera)

Clarity of underwater vision

Ability to detect images below the surface of the water from above (and vice versa)

Ability to compensate for idiosyncrasies in refraction (closely related to the factor above)

Ability to compensate for movement (self locomotion as well as movement in the environment)

Formation of a single image versus split vision

Capacity for visual organs to withstand environmental challenges such as cold, pressure, and debris

I have not been able to find information comparing abilities to see and interpret auras.

So which animal has the best vision? I was a few chapters into this book before I realized what a silly question this is. Each animal has a type of vision perfectly adapted to its environmental niche. No eye or set of eyes can function in all areas extraordinarily well, because there are a few areas that are mutually exclusive and so it’s a choice between specialization or compromise. If I did have to pick the animal with the best vision, however, it would be any member of the ape family, including humans. No doubt many will not believe me and will dismiss this as more anthropocentricism. I say this because while there are animals who outperform us in every area of vision, except perhaps pattern recognition, our eyes function competently in a wide range of environments and circumstances. Our eyes do little that is spectacular but almost everything well. This is probably the main reason we have adapted to so many environments around the globe.


Source

Sinclair, Sandra. How Animals See: Other Visions of Our World. New York: Facts on File, 1985.

Photo credits: Eagle–Vtornet; Chimpanzee–Thomas Lersch