Kittens are born with blue eyes due to the absence of melanin in their irises. Melanin is the pigment that gives color to the hair, skin, and eyes of humans and animals. In kittens, the melanocytes (cells that produce melanin) in their irises have not yet fully developed, and so their eyes appear blue because of the scattering of white light through the iris of the eye. Refracted (scattered) white light is the same effect that makes the sky blue. Image: MikeB As kittens grow older, their melanocytes become more active and start to produce melanin. This can cause a change in eye color from blue to green, yellow, or brown. The exact timing of this change in eye color can vary depending on the breed of the cat, but it typically occurs between 6 and 12 weeks of age. It's worth noting that some cat breeds, such as Siamese and some other pointed breeds, have a genetic trait that causes them to retain their blue eye color into adulthood. However, for most cats, blue eyes are a temporary f...

Domestic cats have slitted eyes, also known as "vertical pupils," for a very specific reason: to help them hunt prey. Image: MikeB The vertical shape of their pupils allows cats to control the amount of light entering their eyes, which is essential for hunting at dawn and dusk when light levels are low. The pupils can dilate to let in more light or constrict to reduce the amount of light entering their eyes, depending on the situation. The slit shape also helps cats to focus on their prey, as it provides them with a greater depth of field than a round pupil would. This allows them to judge distances accurately and pounce on their prey with precision. In addition, the vertical pupils may also help protect the cat's eyes from damage. By closing to a very narrow slit in bright light, the pupil reduces the amount of harmful UV radiation that enters the eye. It achieves this by working in conjunction with the eyelids which pass down over the slit like a blind at a window. A ca...

The video and the pictures from the video tell you what to look for when sexing kittens. Both the images below are screenshots from the video. The woman is holding the kittens on their backs with their tails at the bottom of the image. I think that you'll agree that the images are helpful. Male Female The important difference to make between males and females is that the female vulva is closer to her anus than the male penis is to his anus. In the adult cats it's about twice the distance at 1 inch compared to half an inch. I think this difference is perhaps the key to sexing kittens.