Worldwide, around a billion people have a disability, says the World Health Organisation.
In Europe and America, this is one in five people. And since they are less likely to be in work, their poverty rate is about twice as high.
So technologies that could help disabled people contribute more in the workplace – and improve their quality of life – are surely welcome.
And it also makes good business sense.
If a million more disabled people could work, the UK economy alone would grow 1.7%, or £45bn ($64bn), says disability charity Scope.
The eyes have it
Motor neuron disease affects 400,000 people worldwide, including renowned scientist Professor Stephen Hawking. Multiple sclerosis affects 2.3 million.
But neurons controlling eye movement are more resistant to degenerative diseases. This is also true of other parts of the face, like the cheek, which Prof Hawking uses to communicate.
US company LC Technologies has invented a device that enables people to control a computer using just their eyes.
Eyegaze Edge is the latest invention of the company, which was founded in 1988 by a group of engineers in a basement.
It solved the basic scientific problems then, but the early device was cumbersome and very expensive.
“We crammed it in back of a single-engine plane and took it around to towns where there was a need,” says medical director Nancy Cleveland.
“Now, it fits in a suitcase in a commercial aircraft.”
The technology behind Eyegaze is called Pupil Centre/Corneal Reflection, or PCCR. A tablet is set up in front of the user, with a small video camera underneath. A near-infrared LED (light-emitting diode) light illuminates the user’s eye.
The camera then measures the distance between the centre of your pupil and the reflection of LED light on your cornea – the transparent bit of your eye at the front.
This tiny distance shifts as your gaze changes, and this enables a computer to work out exactly where you’re looking.
“People have done all kinds of interesting jobs,” says Ms Cleveland, “and all they had was the ability to move their eyes.”
She says about 12 books have been written using the device.
A similar device is the HeadMouse Nano, recently developed by Texas-based Origin Instruments.
A camera tracks the movements of a reflective dot stuck to the user’s forehead, and these motions control a computer cursor.
Selections are made using a “sip-puff” switch in the mouth, or by dwell time – how long the head stays in a certain position.
It requires slightly more motor ability in its users, but is cheaper.
“Lately, we’ve reduced size and power consumption,” says Origin’s vice president Mel Dashner, who worked on tracking devices for aircraft during the Cold War. “We’re mainly riding the wave of cell phone technology like everybody else.”
There are about 39 million blind people in the world, according to the World Health Organisation. But 90% have at least some level of light perception.
So Stephen Hicks, a neuroscientist at Oxford University, has developed “smart glasses” that accentuate the contrast between light and dark objects.