High-speed trials on a 200mph motor race track have been helping scientists understand how we see the world.

Researcher Ben Tatler is part of a team at Sussex University which has been studying a racing driver's vision to find our how our eyes work.

He said: "We are very visual creatures but our understanding of the way we see is limited.

"We have been carrying out experiments to discover how the eye extracts information to help us to co-ordinate a particular task.

"We started out looking at sedate actions such as making a cup of tea and playing cricket. But the best way to find out how something works is to push it to the limit.

"That's exactly what a racing driver is doing to his visual skills when he is hurtling around a track at 200 mph."

Researchers commandeered the help of Formula 3 racing driver Tomas Scheckter.

They developed equipment to monitor where his eyes looked and recorded his progress as he drove round Mallory Park in Leicestershire.

Mr Tatler said: "We added a camera to the top of his helmet facing out along the track and another near his chin with a mirror reflecting his eye into the lens so we could record the iris movements.

"We got a double picture, of what he was looking at and of the eye doing the looking.

"In many ways, this was the easy bit. It has taken months of careful analysis to plot the results from six laps of the track."

The team studied the images to build an understanding of the visual strategy of a high-speed driver.

Mr Tatler said: "We get the impression our eyes work like a video camera directed by the movement of the head. But it's not like that at all.

"At any one time, we are seeing only a tiny portion of the scene. The bit we see clearly is about the size of a thumb print held at arm's length. The rest is blurred.

"To get the full picture, the iris flicks from location to location, feeding thumbnail-size images to the eye like a series of photographic stills.

"The brain collates all the information and gets rid of the blur.

"From looking at movement of the iris, we can work out which bit of the driver's view is the clear point and mark that with a dot on the picture of the track.

"This enables us to find out where he was looking at any point on his journey."

Every frame of the video footage was manually analysed and marked showing where the driver's vision was focused at every moment.

Mr Tatler said: "We found for much of the time he drove from memory along his racing line, the path drivers favour to drive at their fastest round the track.

"The video showed Tomas was moving his head in the direction he was to steer the car a second later and using his eyes to check this movement had placed him where he wanted to be.

"When overtaking, he had to process even more information. His iris flicked around the track, to achieve the manoeuvre and stay on his desired path.

"The driver has to gather rapid visual input and select the right details in time to prevent a crash. We were able to observe the process in detail with our frame-by-frame study.

"It was the first time anyone has been able to get access to a racing driver for research of this kind."

The researchers are considering further studies involving a racing driver negotiating a track he has never circuited before. This will show whether past practice on the racing line affects his way of looking where he is going.

Mr Tatler said: "There is huge potential to further the bounds of our knowledge about the eye from our observations."

*www.sussex.ac.uk