Scientists have long speculated on the evolutionary advantage of a hammerhead shark’s widespread eyes.
University of Hawaiʻi at Mānoa zoologist Timothy Tricas and two Florida Atlantic University colleagues developed a vision test to find out.
Using beams of light and brain sensors with different species, they determined that the wider a shark’s head, the greater the binocular overlap of its eyes.
Remarkably, the sharks can also see above and below them at all times and, by moving their heads, much of what is behind them as well. That may confer benefits both in catching prey and avoiding predators, the scientists suggest.