“Dogs see only in black and white.”

The notion that our canine companions perceive the world in only shades of black and white is a widespread belief, but it's a myth that has been thoroughly debunked by modern science. This misconception largely originated from a 1937 dog training manual by Will Judy, founder of National Dog Week, who claimed dogs possessed poor vision and saw the world in grays. The idea gained further traction in the 1960s when some researchers incorrectly theorized that only primates could discern colors. Early scientific studies on animal vision, limited by the technology of the time, also contributed to this erroneous conclusion, suggesting dogs were entirely colorblind. Popular culture, like animated films depicting a dog's point of view in monochrome, further cemented this idea in the public consciousness.

However, contemporary research into canine anatomy and behavior has painted a much more colorful picture. Unlike humans, who typically have three types of cone cells in their eyes for perceiving red, green, and blue (trichromatic vision), dogs possess only two types of cones. This gives them what is known as dichromatic vision. Studies in the late 1980s were pivotal in demonstrating that dogs can indeed see colors, specifically within the blue and yellow spectrums.

Therefore, while dogs don't experience the full vibrant palette that most humans do, their world is far from black and white. Their vision is akin to a person with red-green color blindness; reds and greens appear as various shades of yellow, gray, or brown. This means a bright red toy tossed in green grass might blend in for a dog, appearing as a muted brownish-yellow against a yellowish-gray background. People commonly believed the myth because of these historical assertions and the general understanding that dog vision differs from human vision, leading to an oversimplified conclusion of no color perception at all. In reality, their dichromatic vision is well-suited to their evolutionary history, which prioritized excellent low-light vision and motion detection over a broad color spectrum for their nocturnal hunting ancestors.