How do a cat's eyes turn green? - briefly
A cat's eyes appear green due to the reflection and scattering of light by the tapetum lucidum, a layer of tissue behind the retina, combined with low levels of melanin in the iris.
How do a cat's eyes turn green? - in detail
A cat's eyes can turn green due to the presence of a specialized layer in the eye called the tapetum lucidum, which enhances night vision. This layer reflects light back through the retina, increasing the amount of light available for photoreceptors to detect. The green coloration often observed in a cat's eyes is a result of the interaction between light and the tapetum lucidum, combined with the pigmentation of the iris. The tapetum lucidum contains reflective crystals and pigments that can scatter light in specific wavelengths, with green being a common result due to the way shorter wavelengths of light are absorbed and longer wavelengths, such as green, are reflected. Additionally, the amount of melanin in the iris influences the eye's color. Cats with lower melanin levels in their irises may exhibit lighter colors, including green, as the tapetum lucidum's reflective properties become more pronounced. Genetics also determine the specific shade of green, as certain genes regulate the production and distribution of pigments in the eye. Environmental factors, such as lighting conditions, can further influence the perceived color, making a cat's eyes appear more vividly green in dim or indirect light.