My iPhone took a bit of water damage and despite it working, there is a blue patch on the screen and white bright line . What to do?

So, I was taking a bath and accidentally a couple of drops of water fell on my iPhone 6. That was enough to damage it, I suppose. I tried the rice method and put it in for 6 days. It worked, and is still working. However, the screen has a blue patch and white bright line as shown in the attached pic. I know i am lucky that the phone works and It works as if it was never damaged. but is there something I can do to restore the screen to it's original beauty? I got the phone as a gift and would not prefer to spend on replacing it. I would buy a cheaper phone if replacing is the only option left. But other than that, what can I do to recover it 💔💔💔💔. The phone is just 4 years old though.