White marks/lines on screem

[white lines on scren]

Hey guys.
I have trouble with my s9+...it is a good phone,still but there is white marks/lines as shown on pictures and I can wipe those but after sometime,this would come back.What to do ? I Dont want to change my phone even this one is a bit  old now but still good enough.

[keith30]

Might be screen burn as your device is rather old now. It may pay to consider getting a new model as your main driver with that one as a backup

[white lines on scren]

As I know,screen burn is a permanent "scar" on display but this one can be wiped with dry cloth,just how ? 

[hannah33369]

It might be where you keep your phone, in a pocket or whatever is causing those marks