What and how do cats see? - briefly
Cats have exceptional vision adapted for low-light conditions, with a higher concentration of rod cells in their eyes compared to humans. This allows them to detect even subtle movements and changes in light intensity effectively.
What and how do cats see? - in detail
Cats possess a unique visual system that allows them to perceive their environment with remarkable acuity and sensitivity. Their eyes are designed to detect movement, discern shapes, and identify objects even in low light conditions. The structure of a cat's eye is adapted for nocturnal activity, reflecting the species' ancestral origins as desert-dwelling predators.
The feline retina contains two types of photoreceptor cells: rods and cones. Rods are responsible for detecting low light levels and are more abundant in cats compared to humans. This abundance enables cats to see effectively in conditions where humans would struggle, such as at dusk or dawn. Cones, on the other hand, are specialized for color vision and function best in bright light. Cats have fewer cones than humans, which means they perceive a more limited color spectrum. While human eyes contain three types of cone cells that detect red, green, and blue light, cats possess only two types—detecting blue and yellow light—resulting in a color perception often described as "bluish-yellow."
One of the most striking features of a cat's eye is the tapetum lucidum, a reflective layer located behind the retina. This layer enhances the eye's ability to capture and utilize available light, effectively amplifying the image formed on the retina. The tapetum lucidum is responsible for the characteristic "eye shine" observed in cats when light reflects off this layer, creating the iconic green or golden glow in their eyes.
Cats also possess a unique structure called the tapetum cellulosum, which is absent in humans. This structure further enhances light reflection and amplification, contributing to the cat's exceptional night vision capabilities. Additionally, cats have a larger cornea and lens relative to the size of their eye, allowing more light to enter and focus on the retina.
The visual acuity of cats is notably higher than that of humans, particularly in low light conditions. While human visual acuity is estimated at 20/20, cat acuity can reach up to 20/100, meaning cats can see objects clearly from a distance where humans would perceive them as blurred. This superior vision is further enhanced by the cat's ability to focus on distant objects with precision, thanks to their elongated eye shape and flexible lens.
In summary, cats possess a highly specialized visual system that combines an abundance of light-sensitive rod cells, a reflective tapetum lucidum, and adaptations for effective low-light vision. These features make the cat's eye a remarkable evolutionary adaptation, perfectly suited to their predatory lifestyle and nocturnal tendencies.