Some iPhone 5 users were reporting on-screen keyboard corruption in the shape of static lines. There were many speculations that this might have something to do with hardware (or even the screen itself) but it looks like we’re looking at a software glitch soon to be fixed via an update.
The information comes from Apple’s support forum and is by no means an official confirmation. There is no Apple support document for the issue (like the one with the purple haze) but a user claims that has spoken to someone familiar with the matter who said that Apple is aware of the problem and are working on a fix. Here’s the quote: “Apple is aware of the issue & that they’re working on it. It will be patched in an upcoming iOS update. It’s confirmed to be a software issue. Why it only happens on some devices, she didn’t have details. The bottom line is that they’re working on it now & we will have a solution”.
The problem has been reported to appear on those screens where the keyboard pops up to enter the Apple account details. There have been also sightings of the issue on certain icons as well as individual letters. We’re looking forward to seeing a fix as soon as possible, even if it addresses a small chunk of the user base who experience the problem.
Source: Apple Support Communities