Why do the eye of cat glow at night when seen by means flashlight or a cars headlights?

The "glowing" eyes of cats in the dark are not actually glowing, but rather reflecting light. This phenomenon is called tapetum lucidum.

Here's how it works:

* Tapetum lucidum: This is a layer of tissue located behind the retina in the eyes of many animals, including cats, dogs, and some other mammals.

* Reflecting light: The tapetum lucidum is composed of crystals that act like tiny mirrors, reflecting light back through the retina.

* Increased light sensitivity: This reflection allows the animal to see better in low light conditions, as the light is effectively "recycled" through the eye.

When a flashlight or car headlights shine on a cat's eyes, the tapetum lucidum reflects the light back, making the eyes appear to glow.

Here's why this is beneficial for cats:

* Nocturnal hunters: Cats are crepuscular (active at dawn and dusk) and nocturnal (active at night) animals, so their enhanced night vision is crucial for hunting prey.

* Low light conditions: The tapetum lucidum allows cats to see in very dim light, giving them an advantage over prey and predators.

So, while it might look like a cat's eyes are glowing, it's actually the light being reflected back by the tapetum lucidum, allowing them to see better in the dark.