Yes, you read the headline correctly. BreathalEyes is an iPhone app that can measure an individual's blood alcohol content, and it allegedly does a pretty good job at it. How can that be possible you ask? Well, the application takes advantage of a phenomenon known as Horizontal Gaze Nystagmus, which is an involuntary movement of the eyes, and alcohol use is one of the causes for it. All it takes for the trick to be performed is a scan of the subject's eye by using the iPhone's camera. The software should manage to measure BAC within a 0.02% to 0.17% range.
However, before you take out the booze and test it out, keep in mind that BreathalEyes is for entertainment purposes only, so don't count on it when precision is of importance. And, of course, don't even think of driving after drinking, no matter how intoxicated the app should say you are. With that out of the way, feel free to grab the app from the App Store, or check out its video demo embedded below. It is currently priced at $0.99 and will probably grab people's attention on that New Year's party you are throwing.