Getting behind the wheel of a car after having a drink or two is always risky – you may feel perfectly fine, able to do maths, whatever. But the moment you see a roadblock, you’re not too sure if you’ll pass the breathaliser. Why not check your blood/alcohol level using a new app for your iPhone, BreathalEyes?

The BreathalEyes app for the iPhone and iPod Touch works uses the device’s camera to measure the level of Horizontal Gaze Nystagmus (HGN)—basically how twitchy your eyes are—then calculates your BAC within .02 percent, according to the developer.

While this app is fun to use, especially after having a few, it does get a little confused by environmental variables, such as if you’re at a high altitude, or if you’ve been indulging in any other drugs that evening. So don’t use it as a means to justify getting behind the wheel of a car.

Disclaimer: An app can not tell you when you are safe enough to drive, and can not be used in court as a defense for driving drunk. Don’t be a fool. If you’ve had too much, or think you’ve had too much, get a taxi home, or catch a ride with the designated driver.

[Source: iTunes]