Following reports of people being able to steal an iPhone's passcode or passphrase by watching someone enter it over their shoulder before stealing the phone itself, it appears that Apple might have the answer. The issue with iPhones stolen in that way is that the owner's iCloud account could be compromised as a result of the unlocked iPhone but Apple's plans seem to be designed to ensure that nobody can snoop at your iPhone's screen in the future.
That's according to a new report by AppleInsider that looks at two different patents that could potentially fix this issue for good.

One of those patents appears to relate to a privacy film that could be applied to a curved display, putting a protective layer on the screen to ensure that people can't read it when they are standing at an angle to it. This sounds similar to the privacy screen protectors you can buy online, and they're less than ideal. We have to imagine that Apple will have something better up its sleeve though.
The other approach is via a different patent which appears to use a new display that would change the angle at which a device could be read depending on the situation. If you're off-axis, you can't see what's happening on the display. At least, that's the theory. It also appears that the feature would be able to hide only specific colors as well, opening up more possibilities for different methods of implementation.
All of this is likely well out into the future though, and it's important to remember that not all Apple patents turn into shipping products that you can buy on store shelves. But there's no doubt that privacy is a key feature for Apple so perhaps this is a pair of patents that may well come to fruition.