For years, it has been a stereotype that people who wear glasses are brighter than their bare-faced counterparts.
Now, new research has proven that those who wear specs really are more intelligent than people with perfect vision.
University of Edinburgh researchers found significant links between intelligence and poor eyesight while conducting the world’s largest genetic study of cognitive function.
The study analysed genetic data from 300,486 people aged between 16 and 102 who had taken part in 57 studies in Australia, Europe and North America.
Those who participated took part in a variety of thinking tests, and the results were tallied into a general cognitive ability score.
Those who scored the highest in the cognitive tests were 30 per cent more likely to need glasses, compared to those who scored poorly.
The study also showed links between higher cognitive ability and genes known to play a crucial role in good cardiovascular health.
Unfortunately, the study’s design meant researchers were unable to say why there is a correlation between a person’s intelligence, poor eyesight, and cardiovascular health.
Scientists believe the extensive study could help combat Alzheimer’s disease.
The team found 148 genes linked to having better thinking skills, such as memory, reasoning, speed of mental processing and spatial awareness.
Microsoft co-founder Bill Gates, the richest person on the planet for 18 of the past 24 years, is nearsighted and needs glasses to see. The links between glasses and intelligence were uncovered in the world’s largest genetic study of cognitive function
Fifty-eight of these genes have never been reported before.
Scientists said the results could help understanding of the declines in cognitive function that happen with illnesses such as dementia.
Dr Gail Davies, of University of Edinburgh’s Center for Cognitive Ageing and Cognitive Epidemiology (CCACE), who led the analysis, said: ‘This study, the largest genetic study of cognitive function, has identified many genetic differences that contribute to the heritability of thinking skills.
‘The discovery of shared genetic effects on health outcomes and brain structure provides a foundation for exploring the mechanisms by which these differences influence thinking skills throughout a lifetime.’
As well as having better thinking skills, the genetic areas are also associated with better cardiovascular and mental health, decreased risk of lung cancer, and longer life.
Those who participated in the study had all taken a variety of thinking tests which were summarized as a general cognitive ability score.
Participants also had genetic testing that examined their DNA and none of the people had dementia or a stroke.
Lead researcher and CCACE director Professor Ian Deary said: ‘Less than a decade ago we were searching for genes related to intelligence with about 3,000 participants, and we found almost nothing.
‘Now, with 100 times that number of participants, and with more than 200 scientists working together, we have discovered almost 150 genetic regions that are related to how clever people are.
‘We’ve also learned that we need even larger studies to see more of the picture. We also need to study our results closely to see what they can tell us about the possibility of understanding the declines in cognitive function that happen with illness and in older age.
‘One thing we know from these results is that good thinking skills are a part of good health overall.’
The study, published in Nature Communications, involved researchers in Australia, Austria, Croatia, Finland, France, Germany, Holland, Iceland, Ireland, Norway, Sweden, and the US.