Why do cats' eyes turn green? - briefly
Cats' eyes may appear green due to the reflection of light off the tapetum lucidum, a layer of tissue behind the retina that enhances night vision and can create a greenish glow.
Why do cats' eyes turn green? - in detail
The phenomenon of cats' eyes appearing green is primarily linked to the unique structure and function of their eyes, particularly the presence of a reflective layer called the tapetum lucidum. This layer, located behind the retina, acts as a mirror, reflecting light that passes through the retina back into the eye. This reflection enhances a cat's ability to see in low-light conditions, a trait essential for their nocturnal hunting behavior. The tapetum lucidum is composed of specialized cells containing crystalline structures that refract light. When light enters a cat's eye and interacts with this layer, it can produce a greenish glow, especially when viewed in dim lighting or under artificial light sources like flashlights or camera flashes.
The specific color of the glow, including shades of green, depends on the composition and density of the tapetum lucidum, as well as the angle and wavelength of the incoming light. Cats with a higher concentration of riboflavin or zinc in their tapetum lucidum tend to exhibit a more pronounced green reflection. Additionally, the pigmentation of the iris and the overall structure of the eye influence the final appearance of the reflected light. While green is a common color observed in many cats, variations such as yellow, blue, or even red can occur depending on individual differences in eye structure and genetics. This fascinating adaptation not only contributes to their exceptional night vision but also creates the striking visual effect of glowing green eyes, which has captivated human observers for centuries.