The Pupils Of The Cat: Dilated, Vertical… All The Explanations

You may have noticed that cats have vertical, slightly oval pupils. But when these expand, our felines have round pupils.

How can cats’ pupils change from one shape to another? Why this change? And what does that mean? We review all the shapes that the eyes of our cats take!

The Contracted, Narrow And Vertical Pupils Of The Cat

When your cat has constricted pupils, they are narrow and form an oblong vertical pattern, reminiscent of slits. The vertical pupils then give it feline and wild looks, resembling to be mistaken the eyes of a snake.

However, this pupil shape is completely normal in cats. Indeed, they can meet on several occasions:

• The cat has narrow and vertical pupils due to an excess of light, it contracts its pupils to avoid an excessive entry of light, which would simply dazzle it,
• The cat has contracted pupils in reaction to an emotion such as fear or pleasure, but also because it is in the hunting phase and is preparing to attack a fly, a mouse, or simply your toes!

As you will have understood, the cat’s pupil can change in size (like that of humans), but also in shape, to adapt to light or indicate their predatory status.

Did You Know ?

A vertical pupil is observed in predators to assess the distance that separates them from their prey and maintain a quality visual field regardless of the light. On the other hand, herbivores, which constitute one of the preferred prey of cats, often have horizontal pupils, to have a panorama of their surroundings and escape their predator!

The Elliptical, Partially Dilated Pupils Of The Cat

We speak of an elliptical pupil when the latter is neither vertical nor round. It is actually partially dilated, giving the cat’s eyes a wide pupil whose shape remains oval with a vertical orientation.

This type of pupil is more easily found in cats when the light is moderate, either in broad daylight with an overcast sky, or at dawn or dusk. It is during a transition phase that the cat has elliptical pupils, to gradually get used to light or, on the contrary, to darkness.

Of course, the cat’s pupils are also elliptical for a short time when it switches from vertical pupils to round pupils, and vice versa.

Did You Know ?

The cat, in comparison to the human, has proportionately larger eyes. This size advantage gives him a field of vision of 280 degrees, while it is only 180 degrees in humans.

The Dilated Or Round Pupils Of The Cat

A cat’s pupils are perfectly round when fully dilated. This shape of eyes immediately makes your feline friendlier, because it does not evoke a wild animal, and gives it a much softer look.

But don’t be fooled, there is still a predator under this angelic gaze. Indeed, his pupils are completely dilated, simply for one of the following reasons:

• There is very little light, the cat then fully opens its pupils to improve its night vision,
• He is very excited, or on the contrary very frightened, only an observation of his environment and his action will allow you to determine the phenomenon at the origin of the total dilation of his pupils.

In most cases, there is therefore no need to worry when your cat has round and dilated pupils, it is a normal physiological reaction corresponding either to light or to its current state.

Did you know ? Some breeds of cat have rounder pupils than others, unless it’s just an optical effect due to their larger than average eyes. These include the British Shorthair, Persian, Scottish Fold, Ocicat and Singapura.

Pupils Of Different Size And / Or Shape In Cats

This is a veterinary warning sign. If you notice that your cat has one pupil larger than the other, it is anisocoria, often accompanied by eye discomfort. So, you will see other symptoms like eye scratching, red or blue eyes, eye discharge, listlessness, etc.

These symptoms can announce a more or less serious eye disease, such as eye inflammation, retinal disease, glaucoma, corneal ulcer, etc. But it can also be feline leucosis, a tumor or cancer, or even a brain injury.

Consult your veterinarian urgently if your cat suffers from anisocoria!