Anyone who's seen a science fiction movie in the past few decades knows what a retinal scanner is ... and they're awesome.

Padlocks can be broken and fingerprint scanners can be fooled, but there's no way of replicating someone's eye — a retinal scanner is the ultimate biometric security system (and it looks awesome). The only problem is that no one's invented one that's ready to be used on a consumer level. Until now, that is.

Most smartphone upgrades come with a few extra bells and whistles: maybe the screen gets a bit bigger, or the camera takes better pictures, or it's got some fancy new processor inside. Smartphone upgrades are the definition of incremental, they have been for years — but one Japanese smartphone is about to break that trend.

The Fujitsu Arrows NX F-04G, a new smartphone set for release in Japan, comes with a built-in retinal scanner that can be used for a variety of different functions.

Finally, the future has arrived!

Eye-tracking software is nothing new to phone developers, but the Fujitsu Arrow takes it a step further by tracking your iris. If DoCoMo (the company behind the Arrows line) can make good on its claims, then the Arrows NX could be the first phone with an honest-to-goodness retinal scanner.

So, why would you need one? The Arrows NX's retinal scanner can be used for a variety of functions: the most basic is simply unlocking the phone instead of using a pin number or swipe pattern. If it works, it could be a quick, easy alternative to more traditional security measures — after all, it's impossible to forget an eye. The retinal scanner can also be used as a way to verify purchases, though the number of apps that will support the feature has yet to be revealed.

In all honesty, the Arrows NX could be a big step forward. Biometrics are becoming more and more popular everyday, and being able to use your eye for something like unlocking a phone is the sort of sci-fi tech that people love. Hopefully, the tech works as well as DoCoMo claims — if it does, it might not be all that long before phone-based retinal scanners make it to the States.

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