Through some images retouched with one on the visual acuity of different animals, some researchers have shown their level of detail and discovered that the human eye is very precise.
For predators, a moving herd of zebras is just a mass of alternating stripes, for the house goldfish we are quite blurry, but woe to end up under the watchful eye of a bird of prey. In nature there are a thousand and a thousand ways of seeing objects and environments: we human beings perceive everything in a much clearer way than most other animals. But how do other species view?
The answer was given by the researchers of Duke University, in the United States, who in the magazine Trends in Ecology & Evolution compared thevisual acuity of mammals, birds and insects for over 600 species.
Through some images retouched with a special software calibrated precisely on the visual acuity of the different animals, they were able to show their level of detail and discover that the human eye is very precise: surpassed only by the sight of birds of prey and on an equal footing with that of primates, it is up to seven times more acute of the eye of dogs and cats, while it is up to 100 times more accurate than that of mice and gnats.
In the research, Duke University researcher Eleanor Caves explains the ability to perceive detail in insect, fish, mammal and bird scenes, which she investigated from previous behavioral studies or the anatomy of the eye of various animals.
A butterfly seen by a human eye and another butterfly's eye
Visual acuity was assessed in terms of cycles per degree, ie how many sets of dark or light bands in the same degree of visual field a species is able to perceive, before the scene becomes “gray”. What emerged is that many species in nature see their surroundings at a lower resolution than ours. Human visual acuity is in fact comparable only to that of chimpanzees, while it is reduced compared to that of a few other species (corresponds to about 60 cycles per degree). Some birds of prey (eagles, crows, vultures) surpass us, which can reach 140 cycles per degree.
How does the mosquito that is buzzing around us see us? Below is a nice diagram that incorporates the degree of visualization of 6 animals (including the human race):
Read also:
- Cat eyes: how do our feline friends see?
- The world seen through the eyes of animals
Germana Carillo
