Scientists from the University of the Incarnate Word in San Antonio, Texas found that antioxidant compounds in chocolate called flavanols gave a slight temporary boost to the eyesight of up to 30 young adults.
The authors of the study, published this month in the Ophthalmology edition of the Journal of the American Medical Association, say they will need to test their results against a wider sample size.
A group of 30 were given blind tastings of either 72 percent cocoa dark chocolate or milk chocolate.
According to the report, those who were given the dark chocolate reported improved visibility of “small, low-contrast targets within two hours compared with milk chocolate, but the duration of this difference and clinical relevance remains uncertain.”
The nutritional value of dark chocolate compared to its milk chocolate relative has long been understood, with antioxidants commonly thought to improve blood flow.
“The duration of these effects and their influence in real-world performance await further testing,” said a team led by Dr Jeff Rabin.
The study’s authors suggest that the improvement in eyesight is the result of increased blood flow to the retina and visual pathways. However, experts believe further investigation is needed before dark chocolate can be prescribed for people with forms of blindness.