Those who do a lot of driving know how tiring long car trips and night driving can be. And a simple fraction of a second can decide the difference between life and death.

One in four highway traffic fatalities is the result of momentary driver drowsiness, according to the German Road Safety Council e.V. (DVR).

Recently, scientists have developed a device that can prevent several road accidents and save thousands of lives due to drivers falling asleep while driving.

Researchers at the Fraunhofer Institute for Digital Media Technology (IDMT) in Ilmenau, Germany, have developed a device called Eyetracker that tracks a driver's eye movements and raises an alarm before the driver has an opportunity to nod off to sleep.

If the camera modules detect that the eye is closed for longer than a user-defined interval, it sounds an alarm, which could be in the form of flashing lights or a bell or siren, or even a vibrator on the steering wheel.

When used as a driver-assistance system, there can be four or even six cameras keeping watch over the driver's eyes and the camera lenses measure only three to four millimeters in length.

Eyetracker is only roughly half the size of a matchbox and can process up to 200 images per second to detect sleepiness using various factors like line of vision and eyelid position, irrespective of the posture of the driver's head.

Eyetracker can be installed in any model of car and there is no need for a complicated calibration of the cameras. In addition, the system doesn't require any PC or laptop.

What we have developed is a small modular system with its own hardware and programs on board, so that the line of vision is computed directly within the camera itself, notes Prof. Husar of the IDMT.

Since the Eyetracker is fitted with at least two cameras that record images stereoscopically - meaning in three dimensions - the system can easily identify the spatial position of the pupil and the line of vision, according to Husar.

The information is fed out through a standard interface and is stored in a standard interface like USB, thereby connecting Eyetracker directly to the car's trip computer.

Eyetracker can be used in other fields ranging from medicine to marketing.

In medicine, the camera system can assist with eye operations by recording every eye movement of a patient. With this technology, players of computer games can also look around themselves, without requiring a joystick to change their viewing direction. It is also a valuable tool for marketing and advertising researchers with an interest in determining which parts of a poster or advertising spot receive longer attention from their viewers.

Eyetracker is expected to be hit the market by the end of the next year for £100 ($161). The system has already attracted a lot of interest from heavy haulage companies where drivers are prone to serious fatigue.