Why Do Siamese Cats Always Have Blue Eyes?

Siamese cat blue eyes

If you’ve ever looked up from work to see your cat staring at you, then the first thing you probably noticed about them was their gorgeous eyes.

Those vertical pupils and intense stares make cats such beautiful animals, but if you have a Siamese, you may have wondered why Siamese cats have blue eyes and whether ALL Siamese cats have blue eyes.

Siamese cats have blue eyes because they inherited the temperature-sensitive albinism gene, aka the Himalayan gene, which causes their blue eyes. This gene is also responsible for a Siamese’s distinct coat with color points and has been ingrained in the selective breeding process for centuries.

In this article, I will delve into why your Siamese cat has blue eyes and whether having blue eyes is related to any kind of medical condition.

Why Are My Cat’s Eyes Blue?

Siamese cats were selectively bred for modern tastes, including a slim and refined look, compared to traditional Siamese cats, characterized by a rounder body shape, crossed eyes, and more bent tails.

The blue eyes occurred as a genetic mutation in a few Siamese cats and were selected to be part of the breed standard. Because of how well-established blue eyes are as a desirable trait for Siamese cats, all Siamese cats today have blue or blueish-grey eyes.

Siamese cats have the most beautiful blue eyes.

It’s in their genes

The reason behind the blue-eyed trait is that Siamese cats have temperature-sensitive albinism, a recessive gene that cancels the effects of pigments on the cat’s coat and eyes.

(note: recessive means that the gene only manifests itself when it is inherited from both parents)

As such, it’s incredible to consider just how selective the breeding for Siamese cats has been over the centuries to establish blue eyes as a prominent feature in the species.

But why specifically blue?

If temperature-sensitive albinism renders pigments inert, you might wonder why we see such a vibrant blue in our Siamese cat’s eyes. It would be easy to assume a Siamese’s eyes would be colorless or transparent if all pigments were absent.

Bear with me while I get technical about it…

You might have heard that all colors have their specific ‘wavelength’. Some are longer, like reds and yellows, and some are shorter, like blue, purple, and violet.

In short, blue light is better dispersed than other colors, which is the main color reflected in the stroma layer of their eyes.

It’s much the same story as the sky, which we see as blue because that’s the light that our eyes can pick up and is most easily dispersed and scattered.

Longer wavelengths are easily absorbed/filtered by air, while shorter wavelengths tend to scatter in all different directions for our eyes to be picked up.

Technically speaking, Siamese cats should have violet eyes, which has an even shorter wavelength, but our eyes simply aren’t capable of picking those colors up.

Are Blue Eyes Related to Being Cross-Eyed?

It’s worth noting that similar genetic conditions cause (or used to cause) Siamese cats to be cross-eyed.

This genetic defect in their eyes causes an ocular imbalance, so cross-eyed cats must cross their eyes to see straight. This can impair their depth perception and peripheral vision but is usually harmless to the cat.

However, this doesn’t usually affect their quality of life, and cross-eyed cats are still perfectly able to live happy, fulfilled life.

cross eyed siamese cat
A Siamese’s vision is barely impacted by cross-eyedness.

This trait is caused by the same gene that makes Siamese cats have blue eyes, although modern genetics has allowed Siamese cats to keep their beautiful eyes but not struggle with being cross-eyed.

Over time breeders have ‘bred out’ the crossed eyes from Siamese cats as it was a less desired trait by potential owners.

Suggested reading: Cross-Eyed Siamese Cats, Is it Normal?

What Other Issues Does Being Blue-Eyed Cause?

The lack of pigmentation on either layer of the Siamese cat’s eye can significantly affect the eye structure.

Everyone knows how well cats can see at night, but this is less true for Siamese cats.

Their albinism, which also causes their beautiful blue eyes, also lacks an extra layer in their eyes that all other cats have, called the tapetum lucidum.

This layer is positioned at the back of the eye, behind the retina, which reflects the light back into the eye, giving cats unparalleled night vision.

Because of this, Siamese cats often struggle to see well in the dark.

Are Blue-Eyed Siamese Cats Deaf?

Now that we know more about a Siamese cat’s eyes and their albinism, you may wonder, what about their ears?

You may have heard the rumor that many white, blue-eyed cats are deaf. While this is often true, this doesn’t apply to Siamese cats.

Although Siamese cats are partly white and deaf Siamese cats do exist, they are nowhere near as likely to be deaf as white, blue-eyed cats.

65-85% of white, blue-eyed cats are found to be deaf because of a condition called “Congenital Deafness”, from which Siamese cats don’t suffer.

white cat blue eyes
65-85% of white, blue-eyed cats are deaf.

Health Concerns for Blue-Eyed Cats

Many cats love to have a midnight romp around the house, but you may find that your Siamese cat is less active during the night. This is simply because their night vision is not as strong as other cats.

This is nothing to be overly concerned about, it’s totally normal, and your Siamese won’t know any better. It will be more careful at night to avoid bumping into things.

Blue eyes don’t make Siamese cats more prone to diseases affecting the eye, but the breed is susceptible to other eye conditions.

If you’d like to read more about that, have a look at our article titled: “Common Eye Problems in Siamese Cats“.

Our Final Thoughts

Blue eyes are beautiful, whether it’s in people or cats, and the blue-eyed wonder that is the Siamese cat has a special place in our hearts.

Their bright, intelligent eyes make their enchanting personality, chatty nature, and clownish antics all the better.

It’s astonishing to discover that the blue in your cat’s eyes isn’t a result of any pigmentation but rather from a lack of pigment altogether.

Siamese cats bring so much joy to their lives, and their bright blue eyes are a beautiful reminder of their specialty.

Love Siamese Cats?

Then you will also love our other content about this wonderful breed. Have a look at these posts on our website.

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Tom Alexander is a life-long cat parent and enjoys sharing a home with his cat Max and his family. Being a devoted cat person, his passion for everything feline and blogging is the driving force behind catnfriends.com. As the founder and editor at Cat & Friends, Tom aims to provide an interesting and great resource for cat owners.

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