Why Do Siamese Cats Have Blue Eyes? Exploring the Genetics and Myths Behind the Trait.

The color of a cat’s eyes is closely related to the color of its coat. In general, cats with lighter coats tend to have lighter-colored eyes, while cats with darker coats typically have darker-colored eyes. This is because the same gene that controls coat color also affects the production of pigment in the iris of the eye.

The Role of the Enzyme Tyrosinase

The production of pigment in the iris is controlled by an enzyme called tyrosinase. In Siamese cats, a mutation in the gene that codes for tyrosinase leads to decreased pigment production, resulting in the characteristic blue eyes. This same mutation also affects the production of pigment in the fur, which is why Siamese cats have a distinctive “pointed” coat pattern, with darker fur on their ears, faces, tails, and feet.

The Inheritance of Blue Eyes in Siamese Cats

The gene that controls eye color in Siamese cats is inherited in a dominant manner. This means that if a Siamese cat carries a copy of the mutant gene, it will have blue eyes. However, if a Siamese cat does not carry the mutant gene, it may have green, yellow, or even brown eyes.

The History and Mythology of Siamese Cat Eye Color

Ancient Beliefs and Legends Surrounding Siamese Cat Eye Color

Siamese cats have a long and rich history that dates back to ancient Siam (now Thailand). According to legend, Siamese cats were the protectors of the royal palace and were considered sacred animals with mystical powers. It was believed that the blue eyes of Siamese cats were a symbol of their connection to the spiritual world and that they could see and communicate with ghosts and spirits.

The Role of Western Breeders in the Development of Modern Siamese Cats

Siamese cats were first imported to the western world in the late 1800s, where they quickly became a popular breed among cat lovers. However, the original Siamese cats were quite different from the modern Siamese cats that we know today. They were larger, stockier, and had a more rounded head and body shape. Over time, western breeders selectively bred Siamese cats to create a more slender, elegant, and refined appearance, which eventually led to the modern Siamese cat breed that we see today.

The Variations of Siamese Cat Eye Color

The Differences between Cat Breeds with Blue Eyes

While all Siamese cats have blue eyes, there are other cat breeds that also have blue eyes, such as the Balinese, Birman, and Himalayan. However, the shade of blue can vary between these breeds, with some having a lighter, more icy blue color, while others have a deeper, more intense shade of blue.

The Development of Siamese Cat Eye Color over Time

The blue eyes of Siamese cats have evolved over time, as breeders selectively bred cats with the desired traits. Early Siamese cats had crossed eyes and a more moderate blue eye color, but over time, breeders selected cats with a more intense blue color and a straighter eye alignment. This led to the development of the modern Siamese cat breed, with its piercing blue eyes and elegant appearance.


In conclusion, the blue eyes of Siamese cats are a result of a genetic mutation that affects the production of pigment in the iris of the eye. This mutation also affects the production of pigment in the fur, leading to the distinctive “pointed” coat pattern of Siamese cats. The history and mythology of Siamese cats have also contributed to the fascination with their blue eyes, which have been associated with mystical powers and spiritual connections. While other cat breeds also have blue eyes, the shade and intensity of the blue can vary between breeds, and the development of Siamese cat eye color over time has been shaped by the selective breeding practices of cat fanciers.

ThePetFaq Team