Cat Eyes

Did you know that cats can see clearly with only 1/7 of the light a human needs?

The cat's eye presents several characteristics that make it the domestic mammal best adapted to night vision. They have a lucent carpet that reflects 130 times more light than the human eye fundus; a vertical slit-shaped pupil that gives rise to a smaller opening in light conditions, and which at the same time has a capacity to dilate about 6 mm more than the human pupil. Cats also have a very wide cornea, which allows more light to enter the eye, a more posterior location of the lens (or crystalline lens), which produces a smaller but also clearer image, and a deeper anterior chamber, in addition to their retina being very rich in light-sensitive photoreceptors.

Cats can distinguish colors, although with many limitations

There are several studies on color perception in domestic animals. The presence of photoreceptor cones in the retina suggests that these animals have the potential for color vision. Cats have a limited ability and can distinguish two stimuli if they differ greatly in their spectrum. Cats appear to have trichromacy (the ability of the animal to perceive three distinct shades of color: blue, green and red), since they have these three types of cones in their retina, just like humans, but behavioral studies have not yet been able to demonstrate this ability.

When do kittens' eyes change color?

The eyes of kittens are not fully developed after birth. Kittens are born with their eyes closed and only after the first week of life they begin to open their eyes. In the first weeks the eyes appear to be of a grayish blue color, due to the effect of light being refracted on the cornea and due to the fact that the four layers of this structure are still relatively thick. By 6-7 weeks, the eye color begins to change; the iris contains melanocytes, which begin to produce melanin, the pigment that gives the eye its color. The final eye colour, as well as its intensity, depends on the amount of melanocytes present and the amount of melanin produced. There are exceptions, cats with blue eyes or cats with eyes of different colors.