SunOfRa78 wrote:
This is most likely a hardware issue. Screens can develop these issues for no apparent reason. Most likely it needs it's screen replaced.
You can have the screen replaced by either Apple or an independent repairer.
You did well, UNTIL you suggested an independent repair shop. 3rd party shops don't have access to authentic Apple parts, so they'd be putting an inauthentic screen on the Authors iPhone. They'd have a permanent message on their iPhone that inauthentic parts have been installed, Apple won't ever touch an iPhone which has been tampered with by anyone other than Apple or an actual Apple Authorized Service Provider and their iPhone will have NO trade value and resale value would be greatly harmed.