Short-sighted people are more likely to be better educated and intelligent, a study has found. The link was discovered during an investigation into the rise of myopia across Europe.
Rates of the condition among adults has increased from 18% in those born between 1910 and 1939 to over 50% in some groups today - including professional people in their late 40s, the Sunday Times reports.
Researchers from Mainz University in Germany carried out eye examinations and intelligence tests on 3,452 people. They recorded their age and how many years they spent in education.
"A higher cognitive ability was identified in myopes compared with non-myopes. The TOL [intelligence] score increased with the magnitude of myopia," the team wrote in the paper.
"Cognitive ability, which may have a significant genetic component… may be associated with myopia primarily through its impacts on level of education."
The scientists believe that increased reading time - on computer screens or through books - could damage eyes. They also say a lack of time spent outdoors may play a role in the biological pathways involved in eye growth.
- This article has been amended