Self-adjusting glasses

Although an estimated 60-70 per cent of people in the UK wear glasses, only around five per cent of people in developing countries do, due to the cost of the glasses and a lack of access to eye specialists.

Prof Joshua Silver, director of the Centre for Vision in the Developing World at Oxford University, has devised glasses which can be adjusted according to the severity of a person’s sight problems.

Plastic syringes full of silicone oil can be attached to each side of the thick frames, allowing the wearer to pump as much liquid into the glasses as needed to correct their eyesight. Those with more severe vision problems pump in more and those with milder problems pump in less. The syringes are then detached.

A pair of the glasses costs around $19, but Prof Silver hopes this cost can eventually be reduced. He aims to start by distributing a million pairs of the glasses, which are made in China, in India in the next year.