If you wear glasses (or contact lenses), it could be a sign that you're more intelligent than your pals with 20/20 vision.
That's according to new research from the University of Edinburgh, which aimed to identify genes linked to higher intelligence and how they appear in relation to other genes.
The researchers analysed data from more than 300,000 people who'd taken a variety of problem-solving tests designed to evaluate their cognitive skills. They were then given a general cognitive ability score, and researchers examined their DNA.
According to the findings, those with high cognitive ability scores were around 30 percent more likely to have genes associated with poor eyesight than others. Therefore, they were also more likely to wear glasses.
The researchers identified 148 genomic regions that appeared to be linked to having better cognitive function — 58 of which have not been reported before.
While the study identified trends, it did not investigate why these correlations exist, or what future implications could be. Interestingly though, as well as finding a link between eyesight and cognitive ability, the researchers found genetic patterns associated with intelligence also appeared to signal better heart health, improved mental health and a decreased risk of lung cancer compared to others.
Lead researcher professor Ian Deary said the discovery of gene patterns relating to cleverness could help scientists further research diseases such as Alzheimer's.
"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," he said. "One thing we know from these results is that good thinking skills are a part of good health overall."
The study is published in the journal Nature Communications.