Happy Wednesday, everyone!  Can Cats And Dogs See UV Light When Humans Can’t?  Did you know there are three types of ultraviolet light?  (UVA, UVB, UVC). Unlike humans, many animals see ultraviolet, and a study now suggests that cats, dogs, and other mammals can, too.  Light is made up of a spectrum of colors. Visible light (that humans can see) spans from red to violet and beyond the visible lie ultraviolet wavelengths. Many animals are known to have UV-vision, including insects (such as bees), birds, fish, amphibians, and reptiles, and a handful of mammals (such as mice, rats, moles, marsupials, and bats).

The lens of the human eye blocks ultraviolet light, but in animals with UV-transparent lenses, ultraviolet light reaches the retina, which converts the light into nerve signals that travel to the brain, where the visual system perceives them.

Even in animals whose retinas aren’t very sensitive to UV light, some of the light is still absorbed.  (In fact, humans who have had their eye lenses removed, such as in cataract surgery, without being replaced by ultraviolet-blocking lenses report being able to see in the ultraviolet.)

Cats can do some pretty impressive things, like jump six times their height.  The most impressive of all is their ability to see ultraviolet light thanks to UV-transparent lenses in their eyes that allow UV light to reach their retinas. This will come as little surprise to anyone who’s ever noticed their cat staring at seemingly nothing for minutes at a time, but it’s a fascinating insight into how our feline friends view the world all the same.  In fact, their UV vision actually allows them to see their prey’s urine trail while hunting and distinguish between their prey and a similarly colored background.

When we think of cats in the ancient world, Egypt tends to come to mind first. Egyptians considered felines sacred; some even mummified their pets, but they weren’t the first to hold cats in such high regard.  Evidence suggests they were beaten to the punch by at least 4,000 years: A grave in Cyprus dating back some 9,500 years contained the remains of a human and cat alongside decorative objects such as seashells and polished stones.  Cats aren’t native to the island, meaning they must have been brought there by humans, perhaps “on a kind of Noah’s ark,” as archaeologist Melinda Zeder told National Geographic, theorizing that a number of non-native animals were transported to Cyprus.

How does UV vision help cats?

*Spotting prey: UV variations between a prey animal and its background can make the prey stand out.
*Night vision: Cats have many rods in their retinas, which help them see in dim light.
*Color differences: Cats may be able to see more color differences.
*Other animals that may see UV light: dogs, hedgehogs, ferrets, okapis, and deer.

How does UV vision work in cats?

*UV light passes through the cat’s lens and reaches its retina.
*The retina converts the light into nerve signals that travel to the brain.
*The brain processes the signals into visual information.
*These abilities may help explain why some animals are such good hunters.

Is UV light harmful to cats?

*Yes, UV light can be harmful to cats’ eyes. Just like in humans, exposure to ultraviolet (UV) light can lead to various eye problems in cats, including Corneal Damage.  UV light can cause keratitis, an inflammation of the cornea, leading to pain and discomfort.

How does UV vision help dogs?

*Dogs can perceive ultraviolet (UV) light, which helps them see better in low light conditions, aids in spotting prey, and even assists in finding urine trails for communication.
*Enhanced Night Vision:  Dogs’ eyes are more sensitive to UV light than humans, and this sensitivity, along with a larger pupil size, enhances their ability to see in the dark.
*Spotting Prey:  UV light can help dogs spot camouflaged prey more easily, as certain objects or patterns reflect UV differently, making them more visible
*”Pee Mail” Detection:  Dogs’ urine, especially when dry, can reflect UV light, making it easier for them to follow scent trails left by other animals or to find their own urine markers.
*Evolutionary Advantage:  It is hypothesized that dogs evolved from nocturnal hunters, and the ability to see ultraviolet light may have been a key factor in their survival and hunting strategies, according to Wag.

Is UV harmful to dogs?

Excessive UV exposure harms dogs, can lead to eye conditions like pannus, and potentially increases the risk of certain cancers.  Similar to Humans, dogs can suffer from the harmful effects of UV radiation, including sunburns and increased skin cancer risk.

Eye Conditions:

*Pannus: This condition, also known as chronic superficial keratitis, affects the cornea and is worsened by UV exposure.
*Cataracts: While less common in dogs than in humans, UV rays can accelerate the development of cataracts.
*Squamous Cell Carcinoma: Excessive UV exposure can increase the risk of this type of surface ocular cancer.
*Dogs with Light-Colored Eyes/Skin:  Dogs with light-colored eyes or skin are particularly vulnerable to the sun’s harmful UV rays.

Want more pet health posts, check them out here:

Doggie Eye Boogies And What They Mean

Dog Eye Discharge

References:

The Interesting Facts Newsletter

www.face4pets.org