Efforts to raise educational standards in developing countries have tended to focus on the quality of teachers and the provision of books and buildings, but a study reveals a much simpler, cheaper solution could be the answer.

Giving free pairs of spectacles to children who cannot see the blackboard has dramatically raised school grades, according to a year-long trial conducted by Oxford and Minnesota universities.

The large-scale study of primary schools in the province of Gansu, one of the poorest parts of China, showed that only three per cent of children who needed glasses actually wore them. These are the first results to be revealed from the Gansu Vision Intervention Project, involving 165 schools and 19,000 children aged between nine and eleven.

Optometrists contracted by the project travelled to each town to conduct in-depth eye tests for students, and, if poor vision was confirmed, prescribed appropriate lenses free of charge. By comparing academic test scores before and after the trial, the researchers discovered that after just one year, the children who had worn glasses for the first time gained the equivalent of an extra quarter to a half year of schooling.

The researchers found that 12 per cent of children needed glasses, and yet many did not wear them because of the stigma attached to wearing glasses. Around 30 per cent of those found to need glasses chose not to participate in the study, usually because of the mistaken belief that wearing glasses made young eyes weaken even faster. The spectacles that were provided by the researchers typically cost around $10 (£6) or around $15 (£9) using current exchange rates.

The researchers compared the school children’s academic scores after tests in Chinese, mathematics and science, both before and after the trial. No intervention was taken in 62 schools as part of the randomized controlled trial.

The researchers found that although some children were given eye tests at primary level, many who needed glasses had slipped through the net, largely because vision problems were widely considered to be an issue that was more important for secondary school students rather than those in primary schools. The researchers are now studying the impact of eyeglasses on older children and plan to look at how they can effectively promote the wearing of glasses to children and their parents.

Study co-author Professor Albert Park, from the Department of Economics and School for Interdisciplinary Area Studies at the University of Oxford, said: ‘Thinking as an economist, it’s puzzling that this relatively cheap, quick fix hasn’t happened already. I think that a lot of people who are going around trying to think about how to improve education and learning tend to focus on how we can improve schools, and teachers, textbooks, et cetera. And this problem is a little bit different, because it’s really about the behaviour of students and their parents. Sometimes the simplest solutions are just overlooked and yet this study suggests we have tapped into a whole area of future potential.

‘A lot of potential talent is being wasted in schools, particularly in poorer parts of the world. Two of the UN’s eight Millennium Development Goals focus on education, yet this study shows that school enrolment is only one factor. Our study has identified an intervention that is cheap and relatively simple to implement, yet it dramatically raises school grades. In China, we have discovered there is still a stigma to wearing glasses that has to be overcome. We believe that that by fixing eyesight this way, we raise grades and improve prospects not just for the child but for a country’s economy as it depends on an educated, skilled workforce for its future.’

The researchers collected data from the schools involved in the Gansu Vision Intervention Project in 2004 and followed up with a collection of data on test scores in 2005. The collaboration involved a team of Chinese and international researchers, in cooperation with the health and education officials in Gansu Province.