Glasses with adjustable focus could help the one billion people around the world who have poor eyesight but no access to spectacles.

Joshua Silver from Oxford University, United Kingdom, invented the glasses, which look like ordinary spectacles, except for two knobs on either side of the frame that can adjust the curvature of the lens. Wearers can simply alter the focus as their eyesight deteriorates over time.

This innovation will be particularly valuable in countries where opticians are scarce. Through an agreement with the World Health Organisation and the World Bank, Silver plans to sell up to 400,000 adaptive glasses in Ghana, with another deal for 9.3 million pairs in South Africa.

Link to Independent news story