Asked in Animal Behavior
Do animals and humans see the same?
November 15, 2010 8:59PM
Ah, this is quite a complicated question and depends on a number of different factors. Before addressing vision, however, please remember that humans are animals. That said, there is remarkable diversity amongst this kingdom, and indeed, within our own species (H. sapiens) in terms of this particular sensory system. Some animals only have simple lenses to detect variations in light, whilst other animals have rather complex visual organs. One particular synapomorphy of the order primates is the fact that we (i.e., lemurs, monkeys, apes and humans) have forward-facing eyes with stereoscopic vision. Compare the position of the eyes of a prey species, such as a rabbit, with the position of the eyes of a human. Indeed, the rabbit possesses eyes that have a much wider inter-orbital distance, and are laterally placed on its cranium, allowing this animal to have a greater visual range, which is certainly beneficial when monitoring the environment for potential predators. Primates, like other predatory species (i.e., felids, birds-of-prey, etc.) have eyes that are closer together. Additionally, the way that animals perceive colour depends on the number of rods and cones it possesses, and whether it is active during the day (diurnal), at night (nocturnal), at dusk or dawn (crepuscular) and so forth. Animals that are nocturnal are going to have greater visual acuity at night (greater number of rods), but will see less colour (fewer cones) than animals that occupy a diurnal niche. In sum, it depends on what animals you're trying to compare to the human animal.