A Cool Eye Fact from the Animal World

Hey! Did you know that Santa’s ride—yep, the reindeer—has eyes that actually change color with the seasons?

More specifically, it’s a special part of their eyes called the tapetum (a reflective layer that helps them see in the dark). In summer, it shines gold, but in winter, it turns a deep blue!

Why? It all comes down to changes in the eye’s internal pressure, which affect how the fibers in the tapetum are arranged. Scientists found that pressing on the eyeball can even change how it reflects light!

This mirror-like layer boosts night vision by reflecting light back through the retina—kind of like giving the eye a second chance to “see” the same light. That’s why dogs and cats’ eyes glow in the dark or under night-vision cameras—they’ve got one too!

And get this: reindeer can even reflect ultraviolet (UV) light, helping them survive the super dim, icy winters in the Arctic.

But here’s the fun mystery—how exactly does the eye pressure change with the seasons? And do reindeer outside the Arctic experience this too? 🤔 No one knows for sure… but it’s definitely something worth studying!