Vision varies massively across the animal kingdom; bees can perceive ultraviolet light, owls can see things in brilliant detail, and geckos can somehow see in color when it’s dark. But do you ever wonder how well your goldfish sees compared to you? Well now, thanks to researchers at Duke University, you can certainly get an idea.
Humans as a species aren’t brilliant at seeing in the dark or distinguishing colors, but there’s one thing our eyes are pretty good at – we can see fine details that many species struggle with. To give us a sense of how our ability to do this compares with that of other animals, researchers have looked at the visual capabilities of hundreds of species. Their findings are published in Trends in Ecology & Evolution.
The team were interested in visual acuity, which is essentially the clarity of vision. Our own visual acuity is similar to a chimpanzee’s and is superior to that of most other animals. However, there are exceptions. For example, birds of prey like eagles see fine details twice as well as us.
The team compiled the results of past studies that analyzed the eye anatomy of or conducted behavioral experiments on 600 species of animals. Amazingly, they found a 10,000-fold difference between the sharpest and fuzziest vision. Humans, chimps, and birds of prey were the leaders – weirdly along with octopuses – and closely followed by a whole host of mammals. Perhaps unsurprisingly, various insect species ranked worst.
They then used software called AcuityView to create images that give a sense of how animals see the world based on their visual acuity. Check out a few below.
As you can see, compared to you your cat can see pretty well, but your goldfish a little less so. It’s interesting to observe that the mosquito essentially just sees a blur, which makes sense since mosquitoes very much rely on scent to sniff you out before biting you.
The images also call into question the purpose of certain animal features. For example, below you can see a butterfly viewed through human eyes (left) and butterfly eyes (right). We can easily make out the spots and markings on the butterfly’s wings, but weirdly other butterflies can’t. This suggests that a butterfly’s markings have more to do with deterring or confusing predators than attracting mates, something that is often debated.
The researchers point out that the images they’ve created are simply a representation of an animal’s visual acuity, so what each animal actually sees in real life might be a bit different. This is because the eye takes in a whole host of visual information that the brain then processes accordingly.
“The point is that researchers who study animal interactions shouldn’t assume that different species perceive detail the same way we do,” lead author Eleanor Caves said in a statement.
Still, it’s fascinating to be reminded that eyesight across the animal kingdom varies, and get a sense of how lucky we are to see the world in much better detail than most other creatures.