The Flir One case means that even in complete darkness, users can see the whole picture.

This year's International CES has been awash with hardware accessories for the iPhone and iPad that bring new functions and features.

One of the most interesting is the Flir One. It turns an iPhone 5 or 5S into a night vision camera. The result is that no matter what kind of light is available, users will be able to snap a photo or to simply see exactly what's in front of them.

A great way of negotiating country roads on foot at night, for example. But as Flir suggests, it could be just as useful for finding the cat or for finding the studs or cables in a partition wall before a DIY project.

However, the images aren't of the green-tinged ‘true' night vision variety, they are colorful thermal images, created by detecting heat levels which are processed in order to create the image that appears on screen.

As well as night vision, the Flir One's housing also contains its own battery. When charged it will enable the camera to work continuously for two hours. A rather thoughtful feature is the ability to use that second battery to boost the iPhone itself. With the imaging camera turned off, the case can add an extra 50 percent to the phone's own battery life.

Available in grey, white or gold, the Flir One will ship later this year for $350.

The Flir One was not the only iPhone hardware accessory making its debut at CES.

Some, such as Yellow Jacket's protective iPhone case with integrated 650,000-volt stun gun, have, unsurprisingly shocked many attendees.

But others, such as Mophie's space pack have quite rightly won praise. Morphine is already well known for its Juice packs that combine protection with extra battery life and are currently made for the iPhone, iPad and selected Android devices.

This year the company has decided to take the concept one step further and, as well as extra power, is offering extra storage in the shape of 16GB or 32GB built into the case.