Every Animal That Can See Things Humans Can’t

Dogs are probably the animal most people think they know inside and out, which makes it all the more surprising that their visual world is genuinely alien to ours in ways most owners never consider. The most commonly cited difference is color: dogs are dichromats, meaning their retinas contain only two types of cone cells rather than the three humans have, giving them a color experience roughly comparable to a person with red-green color blindness. So that bright red ball you throw for them in the park? They're tracking it as a dull yellowish-brown blob against green grass, relying more on motion and smell than on any color contrast you assumed was obvious.