Slightly Water damaged iPhone 6

Slightly Water damaged iPhone 6 - 1

Added (1). it was exposed to a very small amount of water, but just enough to make it so the phone is fully functional but when the screen it on (lit up) there's water damage under the screen, along the border of the phone, what should i do?

Help with what?

If it bothers you, you can have the phone repaired. If it doesn't, then… Don't.

It won"t go away on its own, if that's something you're wondering about.

You are lucky that the water didn't do permanent damage. You should take it to a local phone repair shop to have the screen removed, dried out, and replaced. It might cost you $50 or less since no parts need to be replaced.