Help Red flashing boarder lines on screen

Good day

I updated the Android/OS for my Samsung galaxy S3 and I ran 2 updates and the last update was about +80MB. after installing the updates the phone rebooted and i notices a flashing red boarder on the screen and it flashes every time i change one app to another at times but it always comes up when i unlock the phone.

how do i fix this?
 
Top