New studies revealed that daylight plays an important role in preventing short-sightedness. It is not known why daylight is important but some experts believe levels of the brain chemical dopamine play a role. High levels of dopamine in the eyeball have been associated with a lower risk of short-sightedness. Earlier it was believed that short-sightedness was inherited, but scientists are discovering that other factors, such as sunlight exposure, play a role. Short-sightedness, or myopia, is an eye condition that causes a person to see things clearly close-up but struggle to see things when they are far away.
In childhood it is correctable, but it is also linked to the development of severe forms of the eye disorder in adulthood, which increases the risks for potentially blinding diseases such as glaucoma and retinal detachment. A Taiwanese study observed 333 students who spent their break between lessons in the playground. These children, many of whom had formerly spent recess indoors, now spent a total of 80 minutes per day outdoors. Taiwanese scientists are suggesting enforced outdoor playtimes would help stem the growing number of children who suffer with short-sightedness. The condition has rocketed by nearly 65% since 1970 in the US.
The researchers recommended that primary schools should add frequent breaks and other outdoor activities to their daily schedules to help protect children's eye development and vision. ‘Because children spend a lot of time in school, a school-based intervention [such as an outdoors break] is a direct and practical way to tackle the increasing prevalence of myopia,’ said the leader of the study.
A separate study on the impact of daylight exposure on eye development analysed data collected in a 2005 clinical trial that included 235 Danish school children with short-sightedness. Of the children who played outside, significantly fewer became short-sighted or shifted toward short-sightedness, compared with the control school. Of the children who played outside, significantly fewer became short-sighted or shifted toward short-sightedness, compared with the control school.
