Researchers from the Universities of California Berkeley and Durham in Britain have conducted a study on the eyes of animals, all terrestrial vertebrates, which reveals that a lot can be learnt from the eyes of these animals, reported The Guardian.

The study reveals that eyes can indicate whether an animal is a predator or a prey and how tall the animal walks.

According to the The Guardian, Martin Banks, professor of optometry at Berkeley and Gordon Love, director of the Centre for Advanced Instrumentation at Durham, said, "The first key visual requirement for these animals is to detect approaching predators, which usually come from the ground, so they need to see panoramically on the ground with minimal blind spots. The second critical requirement is that once they do detect a predator, they need to see where they are running. They have to see well enough out of the corner of their eye to run quickly and jump over things." 

The study was reported in the journal Science Advances.

The research involved the study of 214 animals that included Australian snakes, cat and dog families, hyenas and mongooses as well as tapirs and rhinoceroses. The researchers explored the relation between the shape of the pupil in the animal's eye and their ecological position.

The study revealed that smaller predators are more likely to have pupils that narrow vertically. Such animals are likely to hunt both during the day and the night. On the other hand, plant-eating animals have horizontally elongated pupils. Taller animals, like lions and tigers, have round eyes and circular pupils.

This research is based on the earlier study on the eye physiology by the late Gordon Walls, a UC Berkeley professor of optometry who published The Vertebrate Eye and Its Adaptive Radiation in 1942.