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5 Cat Pupils Meaning As Indicators Of Their Mood And Health

5 Cat Pupils Meaning As Indicators Of Their Mood And Health

We can’t use words to communicate with our feline friends, but there are some alternatives to get a perspective on their feelings.

A cat’s tail position can help you learn whether your cat is relaxed, alert, or ready to attack. Similarly, observing your cat’s ears can help you determine whether it’s happy, excited, or even sick.

Your cat’s eyes are another means of non-verbal communication. Observing your cat’s pupils can help you understand how they’re feeling and, perhaps, what they are about to do. 

Let’s take a look at the five cat pupils’ meaning and what each of them most likely indicates.

1. Almond-shaped Pupils

If we’re seeking an explanation for the typical appearance of a cat’s pupils, this would be it.

Almond-shaped pupils in your cat indicate that it’s fully relaxed and content. There isn’t any type of threat in your cat’s surroundings, so it doesn’t have to be alert.

This is a neutral pupil condition and something you want to see in your feline friend.

2. Dilated Pupils

white and grey cat with dilated pupils

There are a couple of reasons for dilated pupils in felines. If you notice your cat’s eyes dilate but soon return to their normal shape, there is likely nothing to be worried about.

However, there is also a possibility that this happens due to an underlying health condition. Let’s look at the most common causes of dilated pupils in cats.

Night Vision

When cats are outside at night, their pupils get dilated for them to see better and catch their prey.

They dilate their pupils as much as possible to allow more light to enter.

Good low-light condition vision not only helps cats hunt their prey, but also enables them to protect themselves from predators.


According to Great Pet Care, a cat’s eye muscles are under the control of their sympathetic nervous system.

When a cat gets excited, its nervous system responds in a way that it dilates its eyes.  As soon as the excitement passes, and the cat calms down, its pupils should go back to normal.


You’re also likely to notice dilated pupils in your cat after consuming some medications.

For instance, cats with eye problems usually get prescribed eye drops. This can cause their pupils to dilate.

This is also totally normal and nothing to worry about.


Unfortunately, the change in your cat’s pupils can indicate certain health issues, such as glaucoma.

Glaucoma is a feline eye disorder, characterized by increased pressure within the eye. Besides dilated pupils, the affected cat can also manifest eye pain, squinting one eye, rubbing the eye area, and a watery discharge from the eye.

As soon as you notice dilated pupils together with any of these signs, you should take your cat to a veterinarian.

Feline glaucoma isn’t curable, but it’s possible to relieve the clinical signs by using topical cortisone drops.

3. Narrow Pupils

cat with narrow pupils

Another thing you could notice is your cat’s pupils becoming narrowed.

There are three most common explanations for this change in your cat’s eyes and they all indicate that a cat is aroused.


Your cat could show narrow pupils in moments when it’s completely pleased and happy.

For instance, you can notice this while you’re petting your kitty. In case your cat also purrs loudly, you can be sure this petting session is extremely pleasurable for it!

Other potential situations here are your cat getting a new toy, enjoying its favorite treats, or catching a nice view through the window.


In contrast to displaying pleasure, a cat can also exhibit narrow pupils when it’s feeling angry.

This can indicate that it’s even ready to attack. If you notice this, you should observe the rest of your cat’s body to determine whether it’s about to show aggressive behavior. 

In case it is, its body will look tense, it will growl, and its ears will be laid back.

Aggressive behavior is a severe problem cat parents may face. Kristina A. O’Hanley and her associates [1] investigated the risk factors for aggression in adult cats.

Their study showed how the odds of severe aggression toward other animals were increased with other pets living in the household. Also, cat aggression was more common where owners reported using positive punishment. 

Therefore, to avoid potential aggression, you should use positive reinforcement and socialize your cat from a young age. This is especially important if you have a multi-pet household.


scared cat with narrow pupils

Fear is another reason why a cat’s pupils are narrow.

You could wonder what your cat is afraid of, since there is nothing around that may be scary. Well, cats are highly sensitive and could be afraid of something you don’t even notice.

For instance, anything new in your home can cause fear in your cat. This can be a piece of furniture, or a new human, or a new pet. Most cats are also afraid of loud noises such as fireworks or thunderstorms.

The most important thing is to find the source of fear for your cat and ensure it feels safe and protected in your home.

4. Squinted Pupils

Are your cat’s pupils squinted or half-closed?

This usually indicates that your cat is napping or just about to sleep. It’s in a state of relaxation and nothing around bothers it.

However, it’s possible that this pupil’s meaning isn’t associated with relaxation. If you also notice your cat is blinking excessively and paws at its eyes, there could be a foreign body in its eye.

This is very irritating and painful for felines. Once again, you should take your cat to a veterinarian if you notice these symptoms.

5. Different Sizes Of Pupils

cat with different sizes of pupils

Lastly, you may observe a disparity in the size of your cat’s pupils, a condition known as Anisocoria.

While this condition isn’t fatal, usually not even painful, PetMD points out that the underlying cause is the more important issue here.

Therefore, a veterinarian will need to perform a detailed examination to discover the cause of Anisocoria in your cat.

The following are the most common causes of this condition:

• Disease inside and outside the cat’s eye

• Damage to the retina in the back of the cat’s eye

• Corneal ulcers

• Poisoning

• Parasit, fungal, or viral infections

• Neurological diseases

As soon as you take your cat to a vet clinic upon noticing the different sizes of its pupils, the better it will be for its health.

The veterinarian will decide on the treatment after discovering the underlying cause.

Final Words

cat lying on the floor

It’s amazing to learn that observing the appearance of your cat’s pupils can help you read its mood. 

A cat’s body language in general is very helpful for us to communicate with our favorite pets.

Dilated or narrow pupils can indicate a couple of different meanings. Observing the rest of your cat’s body and its posture can help you determine what is your cat’s exact mood.

More importantly, your cat’s pupils can tell you some essential information about its health. For instance, different sizes of pupils indicate a condition called Anisocoria, which requires veterinary care and proper treatment.

Hopefully, you now have a fair insight into your cat’s eyes. I’m sure it will be interesting to you to observe them frequently and learn more about your cat’s emotions and health.


[1] Kristina A. O’Hanley, David L. Pearl, Lee Niel, Risk factors for aggression in adult cats that were fostered through a shelter program as kittens, Applied Animal Behaviour Science, Volume 236, 2021. DOI, Retrieved December 13, 2023.