“Dogs see only in black and white”

The idea that dogs perceive the world solely in shades of black and white is a long-standing misconception, with its roots tracing back to the early 20th century. This myth gained traction partly due to assertions made in dog training manuals, such as one by National Dog Week founder Will Judy in 1937, who claimed dogs had poor vision and saw only outlines and shades of gray. Further, outdated scientific assumptions in the 1960s, incorrectly suggesting that only primates possessed color vision, helped solidify this belief in the public consciousness. Early studies on animal vision also lacked the sophisticated technology available today, leading researchers to conclude, with limited evidence, that dogs were colorblind.

Modern scientific understanding, however, has thoroughly debunked this notion. Canine eyes possess two types of color-detecting cone cells in their retinas, making them "dichromatic". In contrast, humans are "trichromatic," having three types of cones that allow us to see a broader spectrum of red, green, and blue. This physiological difference means that while dogs do see colors, their perception is akin to a human with red-green color blindness. They can clearly distinguish between blue and yellow hues, but red and green appear as shades of brown or grayish-yellow to them.

People commonly believed this myth because for many years, the scientific tools to accurately study canine vision were unavailable, and early, less precise research suggested a lack of color perception. Additionally, dogs excel in other visual aspects, such as superior night vision and heightened sensitivity to movement, which were crucial for their ancestors' hunting success. These adaptations might have led people to assume that color vision was sacrificed for these more "useful" traits. Understanding their true color perception helps us better interact with our canine companions, for instance, by choosing blue or yellow toys that stand out more clearly against a green lawn.