Ah, anthelioi! Well, you know the big ball in the sky that makes everything bright and warm? That's the sun! And anthelioi are special mirrors that people use to help them see things better when the sun is shining really bright.
You see, sometimes the sun can be so bright that it makes it hard for people to see certain things. But anthelioi can reflect the sun's light away from the thing you want to look at, and that can make it easier to see. It's kind of like when you hold your hand up to your forehead to block the sun while you're watching a soccer game - anthelioi do the same thing, but on a bigger scale!
Anthelioi are especially useful for people who work outside or who need to keep an eye on something important, like a pilot flying a plane or a soldier guarding a base. They can also be helpful for drivers who want to avoid glare on the road, or for anyone who likes to spend time outside on a sunny day.
So that's anthelioi in a nutshell - special mirrors that help people see better when the sun is really bright. Pretty cool, huh?