Ananova:

Car dashboards may soon be fitted with spy cameras to warn drivers if they are falling asleep.

They monitor eye movement and pupil dilation before deciding whether to sound an alarm.

The system is so sensitive it can even work if the driver is wearing sunglasses.

Facelab's eye-tracking technology was developed for computer game players, according to New Scientist magazine.

It has been developed in Australia for Volvo to help reduce the number of tiredness-related road accidents.

Facelab can calculate where the eyes are looking to within three degrees which is accurate enough to see if the driver is looking at the road.

But road safety groups say they are worried the system may encourage tired drivers to push themselves to their limits.