WHY CATS CAN SEE SO WELL IN THE DARK AND WE CAN’T
For those of us who have cats in our lives, it doesn’t take much to understand just how well they can see in the dark. Has anyone else been woken before sunrise by the sound of earrings being delicately nudged off their bed stand by a certain bored feline, or more recently by the sound of Christmas ornaments jangling on the tree in the middle of the night?
It’s no secret that cats do well in the dark, but why? And why do we need to feel around blindly for our beds when we turn off the lights, while our cats can do parkour off every piece of furniture in pitch black?
To start, let’s talk about the core differences between what cats see and what humans see. Simply put, humans can see more vibrant colors and further distances during the day, while cats have a wider field of view, wider peripheral vision, and of course, much better night vision than their human counterparts. Now let’s get into why.
When it comes to night vision specifically, cats have six to eight times more rod cells, which are photoreceptor cells in the retina of the eye that are more sensitive to light. The elliptical shape of the cat eye, as well as its large corneas and tapetum help cats gather more light information in the dark. We’ve all heard of corneas, which are the clear surfaces at the front of the eye that allow light into the eye, but in case “tapetum” is not part of your everyday vernacular, tapetum cells reflect light back to the photoreceptors, creating a second pass at picking up small amounts of light available in dark settings. It is the tapetum that gives the cat eye the appearance of a reflector at night.
All of these specialized features evolved to aid our feline friends in expertly hunting small prey when they are at their most active – at dusk and dawn when lighting is not at its prime.
But this advantage comes at a price. Cats may have more rod cells helping them see clearly at night, but humans have more (and varied) cone cells, which are photoreceptor cells that work best in light. This means humans can see further distances much more clearly and vibrantly during the day.
So while cats may (literally) run circles around us at night, at least we can console ourselves with the fact that the human eye can behold vibrant colors and see for great distances. That’s something I’m sure few of us would opt to give up in exchange for a little night vision.