Guide dogs may soon be out of a job thanks to a high-tech set of glasses and shoes invented by scientists to help blind people navigate the trickiest of terrain.

Researchers at Hong Kong Polytechnic University say the glasses and shoes, which have a built-in computer, detect objects within close proximity through echo location then send a vibrating warning to the wearer.

"Ultrasonic waves are sent out and when they bounce back they are interpreted by a receiver, Research Institute of Innovative Products and Technologies Director Wallace Leung Woon-fong, told Hong Kong's Sunday Morning Post.

"Once an obstacle is detected the shoes will vibrate, perhaps increasing in intensity as the obstacle gets closer," he added.

The shoes will use GPS (Global Positioning System) to tell the wearer where he is and which direction he is going in.

"The shoe will be able to detect steps, holes in the road and obstacles within a 5-centimetre vertical distance," Leung said.

The innovations are based on the award winning "electronic bat ears" sonic glasses developed by the university's Professor He Jufang, which use similar technology to relay information such as size and distance of an object to the wearer.

But some blind people have expressed reservations about the inventions.

"There are so many bumps in Hong Kong's roads. If I wear the shoes I will end up shaking and vibrating all day," said Chow Wing-cheung.

(China Daily August 7, 2006)