What can dogs see? - briefly
Dogs have better low-light vision than humans, thanks to their higher concentration of rod cells in the eye. They also possess a reflective layer behind the retina called the tapetum lucidum, which amplifies light and enhances night vision, but at the cost of reduced color perception compared to human eyes.
What can dogs see? - in detail
Dogs possess an intriguing visual system that is both similar and different from human vision. While humans have trichromatic color vision, with three types of cone cells in their eyes, dogs are dichromats, meaning they have only two types of cone cells. These cone cells contain photopsins that respond to different wavelengths of light, allowing the dog's brain to interpret colors. However, the colors dogs perceive are more limited compared to humans. They can distinguish blue and yellow hues but struggle with greens and reds, which appear as shades of gray or brown to them.
The structure of a dog's eye also differs from that of a human. Dogs have a tapetum lucidum, a reflective layer behind the retina that enhances their ability to see in low-light conditions. This is why dogs' eyes often appear to glow in the dark. Additionally, dogs have more rod cells than humans, which are highly sensitive to light and ideal for night vision.
Dogs also possess superior motion detection capabilities. They can perceive subtle movements that humans might miss, making them excellent at tracking fast-moving objects. This heightened sensitivity is a result of evolution, where dogs' ancestors relied on keen eyesight to spot prey or potential threats in their environment.
Moreover, dogs have a wider field of vision compared to humans. While humans have a visual field of about 180 degrees, dogs can see up to 240 degrees without moving their heads. This expansive field of view is particularly advantageous for detecting approaching animals or other potential dangers from the sides.
In summary, while dogs do not perceive colors as vividly as humans, they excel in low-light situations and have superior motion detection capabilities and a broader field of vision. These adaptations reflect their evolutionary history and underscore the remarkable efficiency of their visual system in various environments.