WHEN your gaze meets someone else’s across a crowded room, you can tell
they’re looking at you by the whites of their eyes. But you’d be struggling with
other primates, as they have totally dark eyes that are intended to camouflage
their gaze from predators, according to researchers in Japan.
Our eyes lack pigmentation in a region around the iris called the
sclera—which is why we call it the “white”. But other primates make
pigments to darken the same region of their eyes.
This costs them energy, and to find out why the animals go to all this
trouble,…
