Vision

Pirates may have worn eye patches for more than just injuries. Since they had to fight while quickly moving between the bright deck and the dark below, they may have used eye patches to keep one eye pre-adapted to darkness.

Humans see three colors; the mantis shrimp sees 16. Most mammals see only two, having lost color receptors during the dinosaur era as nocturnal creatures. Primates alone regained a third through a mutation that helped spot ripe fruit among leaves.

Before World War II, British RAF scientists couldn't crack bomber interception. Commander Grenfell guided fighters by eye, hitting 90% accuracy with the 'gaze heuristic.' This principle later inspired the American Sidewinder missile.

A baseball outfielder does not calculate where a fly ball will land. They simply run while keeping their line of sight to the ball at a constant angle. Falcons hunting ducks use the same method. This instinctive tracking is called the gaze heuristic.