Bees are trichromats like humans.
But instead of red, green, and blue, their three types of photoreceptors
are sensitive to yellow, blue, and ultraviolet light. The ability to
see ultraviolet light lets bees spot patterns on flower petals that
guide them to nectar. In fact, Nilsson says, bees perceive so much of
the ultraviolet range that “they could potentially see more than one
color of ultraviolet.”Unlike human eyes, which have
only one lens, bees have compound eyes composed of thousands of lenses
that form a soccer-ball-like surface; each lens produces one “pixel” in
bees’ vision. That vision mechanism comes at a price—bees’ eyes have
extremely low resolution, so their vision is very blurred. Nilsson calls
this design “the most stupid way of using the space available for an
eye.” If humans had compound eyes that performed as well as our real
ones, he says, they’d each have to be as wide as a hula hoop.
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Unlike humans, birds are tetrachromats. Their four types of cone cells let them see red, green, blue, and ultraviolet together. A few birds of prey have sharper vision than humans, Nilsson says. A large eagle sees with about 2.5 times the resolution that we do.
If Nilsson could truly get inside the head of another animal, “birds would be interesting,” he says. But we can neither sharpen our resolution past human limits nor see ultraviolet light—we don’t have the photoreceptors and brain neurons to make it happen. We can use binoculars to see the distant detail that an eagle would discern, and cameras that convert ultraviolet light to a color visible to our eye, but without such technology “there’s no way of allowing a human to really experience what the world would be like to a big eagle,” Nilsson says.
- Dan-Eric Nilsson author of the new book Animal Eyes (Oxford Animal Biology Series)
[---]
Unlike humans, birds are tetrachromats. Their four types of cone cells let them see red, green, blue, and ultraviolet together. A few birds of prey have sharper vision than humans, Nilsson says. A large eagle sees with about 2.5 times the resolution that we do.
If Nilsson could truly get inside the head of another animal, “birds would be interesting,” he says. But we can neither sharpen our resolution past human limits nor see ultraviolet light—we don’t have the photoreceptors and brain neurons to make it happen. We can use binoculars to see the distant detail that an eagle would discern, and cameras that convert ultraviolet light to a color visible to our eye, but without such technology “there’s no way of allowing a human to really experience what the world would be like to a big eagle,” Nilsson says.
- Dan-Eric Nilsson author of the new book Animal Eyes (Oxford Animal Biology Series)
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