Introduction
There is a common myth that cat’s eyes can change color depending on their mood. Some people believe that a cat’s eyes will change color when they are happy, sad, or angry as a way to communicate their emotions. However, while cat eye color can change over time, it is not an indicator of their mood or emotions. This is an incorrect assumption, and a cat’s eye color is primarily determined by genetics and age. In this article, we will explore the real reasons behind why a cat’s eye color may change over their lifetime.
Cats Have Tapetum Lucidum
Inside a cat’s eye is a structure called the tapetum lucidum. The tapetum lucidum is a reflective layer of tissue in the eye that causes a cat’s eyes to glow or change color in dim light. It’s located behind the retina and reflects visible light back through the retina, increasing the light available to the photoreceptors. This allows cats to see better in low light conditions (Carnegie Museum of Natural History).
The tapetum lucidum is made up of cells containing rod-shaped crystals that act like mirrors. When light enters the eye, some of it passes through the retina and strikes the tapetum lucidum. The crystals in the tapetum lucidum reflect the light back through the retina, giving the photoreceptors a second chance to absorb the light. This is why cats’ eyes seem to glow or change color in low light – it’s the light being reflected from the tapetum lucidum (The Conversation).
Lighting Conditions Impact Color
A cat’s eyes can appear to change colors or exhibit different hues depending on the ambient lighting conditions. This is due to a special reflective layer behind the retina called the tapetum lucidum. The tapetum lucidum reflects light back through the retina, allowing cats to see better in low light conditions. This is why cats’ eyes seem to glow or “shine” in the dark when light hits them.
In bright lighting, the pupil constricts to let in less light, and the iris muscle relaxes, revealing more of the eye’s natural color – often some shade of orange, green or yellow. In low light, the pupil dilates to let in more light, and the tapetum lucidum causes eyes to reflect more blue/green light, so they can appear more blue or green in color.
As lighting shifts from bright to low light, cats’ eyes may seem to shift from yellow/green to a more blue/green hue. But the eye color itself is not changing, just the way ambient lighting reflects and refracts through the eye. So cats’ eyes don’t actually change color with mood or emotion, only with different lighting conditions.
Sources:
https://www.quora.com/Can-you-see-a-cats-eye-color-in-the-dark-if-they-are-lit-up-by-a-flashlight
Health Impacts Cat Eye Color Change
Cats’ eye colors can change due to certain health conditions that impact the eyes. One of the most common is corneal ulcers, which are painful open sores on the eye’s surface. As the Trumann Animal Clinic notes, corneal ulcers can cause a cat’s eye to appear bluish-gray or darker than normal as the ulcer impacts the cornea’s transparency. Proper treatment is essential to prevent blindness.
Over time, many cats develop cataracts which cause the lens to become cloudy. Cataracts block light from properly entering the eye, resulting in the iris looking paler or bluish as less pigment is stimulated. According to the Morris Animal Inn, cataracts typically begin forming in cats around age 10, increasingly progressing to mature cataracts that turn the eyes a distinct blue. As cataracts worsen, surgery may be required to restore vision and eye color.
Breed Impacts Color
The amount of melanin pigment present in a cat’s iris determines its eye color. Melanin levels vary between different cat breeds, leading to distinctive eye colors.
For example, Siamese cats are especially prone to eye color changes as they age. As kittens, Siamese cats have blue eyes due to low melanin levels. But as they mature, their eyes usually darken to a light green or light brown. Other colorpoint breeds like the Himalayan work similarly.
White cat breeds with blue eyes, such as the Turkish Van, tend to have very low melanin. Breeds with amber, yellow and greenish eyes like Persians, British Shorthairs, and Scottish Folds have moderate melanin. While breeds with vivid golden or copper eyes such as Bengals have high melanin levels.
So melanin amounts set the palette for the potential eye colors a particular breed can have. But other factors like genetics and age influence the exact eye color each cat ends up with.
Kittens’ Eyes Change Color
Kittens are usually born with blue eyes. This is because they do not yet have melanin, the pigment that determines eye color, in their irises. As kittens grow, their eyes will change color as melanin develops in their irises.
According to Daily Paws, kittens’ eyes start changing color when they are around 4-8 weeks old. This is when melanocytes, the cells that produce melanin, begin migrating into the iris. The amount of melanin deposited determines the ultimate eye color.
The transition is gradual. At around 2 weeks old, as their eyes open, kittens’ eyes are a dark blue. By 3-4 weeks, they lighten to a grayish blue. From 4-8 weeks, their true eye color emerges, often going through an intermediate green phase before reaching the final hue. This color change occurs whether the cat is destined to have blue, green, yellow, or orange eyes. According to Morris Animal Inn, watching kittens’ eyes transform can be fascinating.
Emotion Does Not Impact Color
Contrary to popular belief, a cat’s eye color does not actually change based on their mood. While a cat’s pupils may dilate or constrict depending on their emotional state, this does not impact the overall color of their eyes.
This myth likely developed because people observe cats’ pupils changing size and incorrectly attribute it to eye color change. As cats experience different emotions like excitement, fear, or contentment, their pupils widen or narrow accordingly, but the iris remains the same color. For example, an excited cat may have large, dilated pupils that make their eyes appear darker, while a relaxed cat will have narrow pupils that reveal more of the colored iris.
According to veterinarians, true eye color change in adult cats is very rare and usually a sign of disease rather than emotion (1). So rest assured that if your cat’s eyes appear to change color, it’s an optical illusion related to pupil dilation, not your cat’s mood.
(1) https://vetrevision.com/common-myths-about-your-cats-eyes/
Other Color Change Myths
There is a common myth that a cat’s eyes can change color based on their mood or emotion, such as turning red when they are angry. However, this is not true. A cat’s eye color is determined by genetics and light exposure, not their emotional state.
According to veterinary sources (https://blog.catbandit.com/can-cats-eyes-change-color-exploring-the-possibilities/), the tapetum lucidum structure at the back of a cat’s eye causes eye shine or eye glow, which makes their eyes appear to flash or change color in different lighting conditions. But this is an optical illusion, not an emotional response.
While some medications or medical conditions like glaucoma can impact a cat’s eye color over time, moment-to-moment shifts in mood or emotion do not cause rapid eye color changes (https://vetrevision.com/common-myths-about-your-cats-eyes/). So if you think your cat’s eyes turned red when angry, it is likely just a trick of the light or your imagination. Their eye color remains the same regardless of their mood.
When to See a Vet
Cats’ eyes can naturally change color, especially when they are kittens, but there are some circumstances when a change in eye color warrants a visit to the veterinarian. Here are some signs that your cat’s changing eye color could indicate a medical issue:
Rapid changes in eye color, especially if only one eye is affected, could signal an injury, infection, or other problem. Cats’ eyes typically change color gradually over weeks or months. Sudden changes require veterinary attention.
Discharge or swelling around the eye. If you notice redness, swelling, discharge, or crusting around one or both eyes, this points to an issue like conjunctivitis that needs treatment.
A change from blue to brown. While kittens often change from blue to another color as they mature, adult cats’ eyes turning from blue to brown could indicate uveitis, glaucoma, or cancer inside the eye. Seek vet care.
Dramatic shifts in brightness or color distribution. If parts of the eye look darker or show markedly different color than the rest, it could signal injury, scarring, inflammation, or cancer that needs veterinary assessment.
If you notice any of these symptoms along with a change in your cat’s eye color, call your veterinarian right away. Rapid veterinary care can help resolve eye issues before they cause permanent damage.
Conclusion
In summary, a cat’s eye color can change for a variety of reasons not related to their mood. The tapetum lucidum, a reflective layer in a cat’s eyes, causes eye color to appear different in various lighting conditions. Health issues like corneal ulcers and cataracts can also impact eye color. Additionally, eye color changes as kittens mature. While many myths persist about cats’ eyes changing color with mood, no scientific evidence supports this claim.
Cats’ eyes do not change color due to their mood or emotions. Their eye color is dependent on fixed factors like genetics, health, and age. So while your cat’s eyes may look different at times, it’s not because they’re happy, sad, or angry. Their eye color changes for other reasons. When in doubt about any eye changes in your cat, it’s always best to consult your veterinarian.