Our eyes provide slightly different views of the world, leaving it for the brain to merge these two views to create a single image that helps us figure out how far away things are.
While this 3D vision is not unique to humans, and can be found in monkeys, cats, horses, owls and toads, the only insect known to have a similar stereo vision is the praying mantis. But does the insect's 3D vision work the same way as that of humans?
A team of researchers the Institute of Neuroscience at Newcastle University in the UK conducted a study to find the answer, and discovered that praying mantises have an entirely new form of 3D vision. The study was published in the journal Current Biology on Thursday.
To further investigate the special case of praying mantises, the researchers created tiny insect 3D glasses that were temporarily affixed to their heads using beeswax. Then they showed the insects a clip of tasty prey hovering right in front of them. The mantis found the illusion so realistic that it tried to catch the prey.
The researchers then showed the insects the complex dot-patterns used to investigate human 3D vision, enabling them to compare human and insect 3D vision for the first time.
Unlike humans, who are incredibly good at seeing 3D in still images, mantises only attack moving prey so their 3D doesn't need to work on static things. However, the researchers found that the insects don't bother about the details of the picture, and just focus on places where the picture is changing.
To make it slightly tougher, the researchers made the two eyes' images completely different. But the mantises could still match up the places where things were changing, and they did it with such precision that even humans couldn't.
"This is a completely new form of 3D vision as it is based on change over time instead of static images," Vivek Nityananda, a behavioral ecologist at Newcastle University, said in a statement. "In mantises it is probably designed to answer the question 'is there prey at the right distance for me to catch?'"
According to the researchers, the latest findings can lead to simpler visual processing for robots.
"Many robots use stereo vision to help them navigate, but this is usually based on complex human stereo. Since insect brains are so tiny, their form of stereo vision can't require much computer processing. This means it could find useful applications in low-power autonomous robots," Ghaith Tarawneh from the School of Engineering said in the statement.