One of the newly discovered fossil compound eyes (center) lies next to trilobite fossils from the same era, known as the Cambrian.
Before the new discovery, the only known Cambrian-era compound eyes belonged to trilobites, which had relatively poor vision.
"Trilobite compound eyes had about a hundred lenses. The new compound eyes have 3,000 lenses, so their vision would have been 30 times as good," Lee said.
Where a trilobite might see blurry patches of light and dark regions, the owner of the newfound fossil eyes would have been able to discern individual objects and creatures.
This would have come in handy if the creature was a hunter, explained study team member Diego García-Bellido, a paleontologist at the Spanish National Research Council in Madrid, Spain.
"Modern arthropods that have acute vision tend to be predators," García-Bellido said. "That's what we see in dragonflies, for example. So we can extrapolate that this guy was most likely a predator."
(Also see "Sea Urchin Body Is One Big Eye.")