A seven-year-old blind boy has been taught to "see" using his ears.
Lucas Murray from Poole in Dorset has learned to use echoes to picture the world
around him - similar to sonar techniques used by bats and dolphins.
He clicks his tongue on the roof of his mouth and from the sound that returns he
tries to work out the distance, shape, density and position of objects.
The echolocation technique has helped Lucas, who was born blind, play basketball
and rock climb.
He was taught the system by blind Californian Daniel Kish, 43, who founded the
World Access for the Blind charity.
Lucas's parents Sarah and Iain saw Mr Kish on TV and asked him to visit.
Mr Kish said: "Lucas is one of the first in the UK to use this technique.
"He is able to click his tongue and determine where things are around him and
what things are around him and he is able to travel comfortably without holding
on to people.
"The click basically emanates a sound which bounces off the environment a bit
like the flash of a camera."
Lucas tells distance by timing how long the echo takes to return and he works
out the object's location by which ear the sound reaches first.
He picks up the density and shape of it by the intensity of the sound bouncing back.
An object moving away creates a lower pitch and one moving closer a higher pitch.
Mr Kish said Lucas determines the qualities of an object by the characteristics
of the sound that comes back.
"He does play basketball, he is able to make it in to the hoop by clicking, he
is actually pretty good at that," Mr Kish added.
"He is doing very well and his mobility is amazing, the best for his age in the UK."