Generally, kittens are born with blue eyes. This blue hue is due to a lack of melanin in the iris when they first open their eyes, typically around 7 to 14 days old. However, the permanent eye color of a kitten is determined by their genes and cannot be predicted with certainty right away. There isn't a magical trick to determine this instantly.
Kitten's Eye Color Development
When a kitten's eyes first open, they often appear blue, which is often referred to as a "blue membrane". This is due to very little melanin present in the iris. Around 30 days of age, this blue hue begins to fade as melanin production starts to pick up. By approximately 60 days, the true, permanent eye color will become apparent. The color is primarily determined by genetics and breed, and the color tends to deepen as they mature. Therefore, when assessing a young kitten's eye color, it's crucial to consider the kitten's age. It's also important to be aware that certain health conditions such as cataracts or glaucoma, can cause a change in eye color and will require immediate veterinary attention.
Eye Color Variations and Breed Standards
Heterochromia, or two different colored eyes, is more commonly seen in breeds like the Shandong Lion Cat and Persian Cat. Domestic Shorthair cats often have yellow or green eyes. White cats are more likely to have blue eyes, while black cats often have green eyes, and orange cats are often found with yellow eyes. British Shorthairs often possess yellow, golden, or blue eyes. Ragdoll cats are known for their striking blue eyes, while British Shorthair Silver Tipped cats are considered higher quality with deep blue eyes. In general, blue eyes are often more sought-after, with the depth of color determining a cat's quality for some breed standards. For example, deep blue is considered rarer than light blue, and golden eyes or copper eyes are considered rarer than yellow.
Factors Influencing Eye Color
While age is a key factor, genetics plays the most significant role in the final eye color. The genes that control melanin production and distribution are the prime determinants. Kittens are often born with blue eyes because melanin hasn't yet been deposited into their irises, but as they grow, melanin production increases and their eye color deepens. Certain breeds have specific eye colors that are highly prized, which is why breeders focus on producing cats with desirable eye color traits.