But in some of the darkest places on Earth– like deep caves, underground tunnels, and certain underwater spots– evolution took a different route. Some animals lost their eyes over time.

Puppies born with a unique feature are an automatic yes for me. Whatever makes them different is what makes them perfect. I'm ...

[Narrator] We'll start at the base of the tree with an early branching fork of animals called cnidaria. The boxed jellyfish actually have 24 different eyes and clusters of six eyes each.

Another animal that is considered to have really beautiful eyes is the Tree frog. They have large, bulbous eyes that come in many different colours, and the most striking and unique are red ...

The presence of the tapetum can be observed at night when a pair of glowing eyes reflects back a flashlight or some other light source. (Interestingly, different animals have different color ...