why do domestic animals have dark eyes while humans have mostly white eyes?

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Our guinea pigs have dark eyes. Why do we have white eyes? – Rhoswen, three, Bristol, UK.

Thank you for the question, Rhoswen. The truth is that guinea pigs also have a white part in their eyes, just like humans. But guinea pigs lead very different lives for us, so they need different eyes to survive.

The white part of our eyes is called the "sclera". It's a hard coating that helps keep your eyes round. The sclera goes straight to the bottom of our eyes. But we can not see everything because it is hidden in the cavity of the eye – the bone cup in our skull where our eyeballs and the muscles that move them sit.

The eyes of the Indian pig also have a white sclera like ours, but it is almost entirely hidden in the orbit. So we see everything we can see in the color of their eyes – it's usually dark brown, but sometimes it's blue or even red.

Eyes to survive

The world is full of strange and wonderful eyes, and each type has special features to help animals survive in their natural habitat. These characteristics have developed over millions of years, passed from parents to babies, according to a process called evolution.

The ancestors of your guinea pigs would have lived in grassy areas, eating plants and trying to avoid being caught by predators. They would have been outside mainly in the darkness of morning and evening.

You have seen that guinea pigs have a big black hole in the center of the colored part of their eyes. This is called the student. The pupil is what lets the light in the eyes.

Having a high student would have helped the guinea pigs' ancestors to see a large area in the shadows – and that would have helped them escape predators and live long enough to have babies with high school students.

Eyes on the sides

The eyes of the Indian pig are also on the sides of the head, rather than on the front as ours. This allows them to see in almost any direction without moving their heads, which is very useful for locating a predator sneaking out from behind.

The disadvantage is that the sight of the guinea pigs is not as clear as ours and that their 3D vision is not very good.

This is because smaller students, like ours, help to see things clearly, and 3D vision works best when both eyes are looking at the same object – which is difficult when they are on different sides of the board. head.

Our human ancestors had to be good at hunting to survive. And having a good, clear 3D view is very useful when you are trying to catch prey for your dinner. That's why humans still have eyes with small pupils, in front of our heads.

Some theories also say that humans have evolved visibly, white sclerosis because we are very social animals, which can help us see where others look – or even how they feel – without words.

Many animals have eyes that are even more different from ours. For example, the eyes of insects are made up of thousands of tiny "mini-eyes" put together. Some animals, like crabs, have eyes on the stems.

Spiders have different pairs of eyes that they use for different tasks, and some mollusks can have up to 100 eyes.

Discover the dragonfly, chameleon, giant squid or mantis shrimp for even more amazing eyes of the animal kingdom.

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