Why do cats have blue eyes? - briefly
Cats have blue eyes primarily due to a lack of melanin in their iris, which is most common in kittens and certain breeds like Siamese or Ragdolls.
Why do cats have blue eyes? - in detail
Cats with blue eyes are a result of specific genetic and biological factors. The color of a cat’s eyes is determined by the amount and distribution of melanin in the iris, which is influenced by genetics. Blue eyes in cats occur when there is a lack of melanin in the iris. This absence of pigment allows light to scatter and reflect in a way that produces the blue hue. Kittens are often born with blue eyes because melanin production has not yet fully developed in their irises. As they grow, their eye color may change if melanin production increases, typically around 6 to 8 weeks of age. However, some cats retain their blue eyes into adulthood, particularly those with certain genetic traits or coat patterns. For example, cats with the white coat gene or the Siamese gene often exhibit blue eyes. The white coat gene, known as the dominant white gene, can suppress melanin production not only in the fur but also in the eyes, leading to blue coloration. Similarly, the Siamese gene, associated with temperature-sensitive albinism, restricts melanin production in warmer areas of the body, often resulting in blue eyes. Additionally, some cat breeds, such as the Ragdoll, Birman, and Balinese, are known for their blue eyes due to selective breeding. While blue eyes in cats are striking and visually appealing, they are not necessarily linked to any specific health issues. However, white cats with blue eyes are more prone to congenital deafness, as the same gene that affects coat and eye color can also impact the development of the inner ear. Understanding the genetic and biological mechanisms behind blue eyes in cats provides insight into the fascinating diversity of feline traits.