How your pet REALLY sees the world | Daily News

How your pet REALLY sees the world

Scientists have mapped out the visual acuity of roughly 600 animal species, revealing just how differently we all see the world.

While humans aren’t the most advanced when it comes to certain aspects of eyesight, our vision is about seven times sharper than a cat’s, dozens of times sharper than a rat or goldfish, and hundreds of times more precise than a mosquito. The fascinating study shows how particular scenes might look from the eyes of several different species. In the study published to the journal Trends in Ecology and Evolution, researchers estimated visual acuity – or the sharpness of vision – across hundreds of species based on the anatomy of the animal’s eye.

Compared to humans, most species ‘see the world with much less detail than we do,’ says lead author Eleanor Caves, a postdoctoral researcher at Duke.

The researchers measured cycles per degree, or the number of pairs of black and white lines a species can discern within one degree of the field of vision before it becomes a blur. Human eyes can resolve about 60 cycles per degree, according to the study.

Some birds of prey, on the other hand, can see as much as 140 cycles per degree. This allows eagles and other predators to pick out small prey from thousands of feet overhead. Other birds see less than 30 cycles per degree, as do fish.

‘The highest acuity in a fish is still only about half as sharp as us,’ says Caves. Images designed to replicate how animals see the world show just how dramatic these differences are. These were made using a program called AcuityView, which takes a digital photo and strips away the spatial detail based on the animal’s abilities.

While a human with less than 10 cycles per degree is considered legally blind, most insects can only see about one. It’s been proposed that butterflies’ wing patterns may be a way to secure potential mates, in addition to thwarting predators.

But, the research suggests this might not be entirely true. ‘I don’t actually think butterflies can see them,’ Caves said. The images in the study only represent their visual acuity, the researchers explain, and other factors come into play when the brain is processing visual information. ‘The point is that researchers who study animal interactions shouldn’t assume that different species perceive detail the same way we do,’ Caves said.



Add new comment