Occasionally, cats will have heterochromia, or eyes of different colors. Cat pupils do more than respond to light. LED lights could become the norm on Britain's roads after the government announced plans to change historic traffic regulations Actually ALL cats' pupils are vertical slits that dilate depending on the amount of light. The slit shape gives them the advantage of having a wide round pupil at night so that they can see better in low levels of light, but the slit allows them to minimise the exposure of light to their retina during the daytime when the light is bright. As hunters who are active at dawn and dusk – the best times for them to stalk prey – cats can actually see as well in pitch black as we can see in full moonlight. Some cats have visible balding around the eyes, while others have a slight thinning of the fur above the eyes, but you need to know why. Hair loss above a cat’s eyes (facial alopecia) commonly occurs as cats grow in size and the fur thins out. End of the road for cats eyes? But if one eye begins to change color over time, there could be trouble brewing, like chronic inflammation or worse. Some big cats prefer hunting during the night, and some find the twilight hours better for finding a meal. This can mean that one eye is blue and one eye is green, or even within one eye, the iris is colored differently. Most people get that some snakes are dangerous and others are not, but not everybody understands how to distinguish between venomous snakes from harmless ones. Can anyone tell me why hers is round and other cats eyes are slitted? Large wildcats have round pupils because their eyes are farther from the ground than domestic cats and big cats don’t have to get as close to prey in order to catch a meal. Among the great cats, lions, tigers and cougars have round pupils. They don’t have to focus on their prey as precisely as small cats, and can make corrections using muscle strength. “Why do my cat's eyes go from round to slit-shaped when exposed to UV light?” For the same reason that the pupils of your eyes get smaller when you’re exposed to UV light. Have you ever wondered why your cat's eyes have those creepy vertical slits for pupils? Their eyes have big lenses and sensitive retinas. A new study suggests the reason may lie in cats' preferred mode of hunting. Many inaccurate traditional guidelines exist, which could cause life-threatening mistakes for laypersons. When it is day time and bright in the room, the cat's pupils will look like a black vertical strip. However, feline hair loss can also be genetic or due to fungal infections, mites, fleas, and stress.