How Does Animal Eyesight Work?


When daylight savings time began in mid-November, your initial reaction was likely being thrilled at the prospect of gaining an extra hour of sleep. But that happy feeling only lasted the first DAY of daylight savings time! The other, less pleasant aspect of daylight savings time is how often we live in darkness. Every day, the sun rises just a little bit later than it did the previous day, and every night, the sun goes down a little bit earlier. It isn't even 5 p.m., and the sun has long been out of the sky.

Not only is it normal for our moods to slightly diminish with these increased hours of darkness, but something else also isn't quite what it used to be during these winter months ahead-our vision! But do you know who LOVES this time of year-our animal friends! Why? Because your dogs, cats, and countless animals who reside outdoors have crystal clear vision, even when darkness arrives.

Let's talk about a few animals who see exceptionally well during the night and highlight how their vision is different from us humans.

Dogs

The Natural History Museum explains that dogs have just two when human eyes have three types of color detecting cells. Dog cones (the cells) specialize in picking up yellow, blue, and ultraviolet light. Because dogs have fewer cones than ours, they can't distinguish between as many colors as we can, and their night vision is comparable to ours. But, at least they're cute, right?!

Cats

According to All About Eyes, cats have 25 rods per single cone in each eye. How does that compare to humans? We only have four rods per single cone, meaning that your cat has far more adequate night vision than humans. These extra rods aren't the only advantage cats have compared to their human companions. While our pupils can widen and narrow to let in more or less light, a cat's pupils can widen considerably more than ours. They also have reflective tissue behind their retinas, which bounces light around inside the eye so that the eye needs less input to see. Long story short? A cat is a good friend to have in the dark hours.

Owls

Sure, owls aren't exactly household companions (unless you live in a world of the Harry Potter books. But their eyesight at night is second to none. All About Eyes explains how even though owls are much smaller than humans, their eyes are nearly the same size as ours. This is useful in capturing as much light as possible, as they swivel their whole heads around their body to effectively capture whatever glimmers of light are available in their (large) fields of vision.

Tarsiers

Tarsiers (small primates) have the biggest eyes and corneas in relation to their body. According to Zoo Portraits, each of the tarsier's eyes is equal in size to its brain and weighs even more. Their huge corneas and a reflective layer of tissue in the back of the eye that reflects light called the tapetum lucidum allow them to take full advantage of any present light, especially at night. It's also believed that they can perceive ultraviolet light!

The winter months ahead mean precious few hours of daylight and a large amount of darkness. But just because the sun goes down in the late afternoon, that doesn't mean our animal friends and their vision suffer. On the contrary, their eyesight thrives in these conditions!

When it comes to making sure your eyes are as healthy as possible for as long as possible, even during this time of year, trust your friends at Carson Optical. Because Carson Optical is family-owned and operated (and has been since 1972), we make it our mission to build strong, personal relationships with each of our valued customers. For more information on our vast array of services, visit our website and contact us to set up your appointment!

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Sources

https://visionsource-coppell.com/2021/08/25/how-does-animal-eyesight-work/

https://www.nhm.ac.uk/discover/how-do-other-animals-see-the-world.html

https://allabouteyes.com/sight-dark-night-vision-works-animals-can-see-midnight/

https://www.zooportraits.com/how-do-animals-see/