What on earth causes freckles?

I think the cause of freckles is sunlight.

I know the importance of sunscreen and I use it almost every day at the office and at home.

Even on my days off, I don't go out much and I always carry an umbrella with me.

I apply sunscreen 365 days a year to take care of my skin.

Freckles? I'm curious to know what exactly causes freckles.

This is also the reason why they appear especially often around the eyes.

Should I change to a functional cosmetic that is good for whitening?

You need to know the cause of freckles to prevent them.

Does anyone know?

I'm worriedㅠ