About 10% of human males (including me) and 1% of human females are missing one of these three receptors. The condition is called colorblindness and is misleading because we can distinguish colors.

The effect is achieved by using “bird’s-eye perspective,” a method that relies on three vanishing points instead of one. Though long known, it was rarely used before the 20th century came ...

Humans can’t see ultraviolet light, but many birds can. ... The resulting videos, which were published on Tuesday as part of a new study, give human viewers a rough animal-eye view of nature.