A link between pupil shape and the feeding behaviour of animals has been made by studying the eyes of 214 species. By modelling how differently shaped pupils collect light, researchers in the UK and US have argued that the shape of an animal’s pupil – the aperture through which light enters the eye – is related to whether that animal is predator or prey.
The study reveals that herbivorous prey animals such as deer and zebras are likely to have horizontal pupils, while predators actively hunting during the day – like cheetahs and coyotes – usually have circular pupils. Furthermore, animals that hunt at night, or both day and night, tend to have vertical pupils. This vertical group includes some foxes, cats and snakes…
Read the full story at Physics World.
Photo credit: David Corby
Richa Malhotra 
It’s true that many models and public figures have a positive canthal tilt, which enhances a more “hunter-like” appearance—where the outer corner of the eye is higher than the inner corner, often giving the eyes a more intense, captivating look.