Screen turns white/vertical lines

Hi,

So I left my phone on charge overnight, and when I picked it up in the morning there were weird white lines on the screen. These lines disappear when I lock the screen/turn the screen off, but after turning it back on and using it to say, text, the lines come back until the entire screen is lighter in colour (apart from around the edges). Again, turning the screen on and off gets rid of them but they come back. I havent dropped my phone recently either, I've only had it for about a mont. 

Any idea?

Please help.

Thanks!

I didn't find the right solution from the Internet.

References talk.sonymobile.com/t5/Xperia-M2/Screen-turns-white-vertical-lines/td-p/959398

Branding Motion Graphics video