Nearsightedness, technically called myopia, is a condition
in which a person sees close up objects clearly, but objects in the distance
are blurred. This condition is often first noticed in school-aged children or
teenagers and tends to get worse during the growth years. If not treated early,
it can lead to severe eye problems in adulthood including glaucoma and retinal
An earlier study of 429 applicants
for Singapore military showed that nearsighted applicants had more education
than their normal-sight counterparts. The study results were published in the
British Journal of Ophthalmology. 'These results underscore the strong
influence of environment in myopia pathogenesis,'
reported the researchers
of the study.
Closer to the present studies is
the findings of a German study published in the journal Investigative
Ophthalmology and Visual Science indicating that experimental animals (chicks)
exposed to bright light for 5 hours per day significantly slowed the
development of myopia in them.
The two current studies were in
the same context but performed on school children.
571 students aged 7 to 11 years,
from two schools were recruited for the first study. Children were divided into
two groups - 333 students in the interventional program, and 238 students in
the control group. The interventions involved encouraging children to go
outside for outdoor activities during school recess. At the beginning of the
study, there were no significant differences between myopia (nearsightedness)
prevalence. After one year, new onset of myopia was significantly lower in the
intervention group than in the control group.
"Outdoor activities during
class recess in school have a significant effect on myopia onset and myopic
shift. Such activities have a prominent effect on the control of myopia shift,
especially in nonmyopic children,"
Pei-Chang at Kaohsiung Chang Gung Memorial Hospital, in Taiwan, the lead
author of this study.
Another study was conducted in
the northern location of Denmark where the length of the day varied from 7
hours in winter to 17.5 hours in summer. In this case, 235 children aged 8 to
14 years found to have myopia during screening for a clinical trial were
included. These children were divided into seven groups, each of which
represented a different seasonal interval.
The researchers, Dongmei Cui,
Klaus Trier, and Søren Munk Ribel-Madsen, tested the axial eye length (a
measurement for myopia) and vision in each group of children at the beginning
and end of their seasonal interval.
The results showed that eye
growth averaged 0.19 mm in children with access to the fewest hours of daylight
and 0.12 mm in those with access to maximum daylight.
"Our results indicate that
exposure to daylight helps protect children from myopia,"
said the lead
author, Dongmei Cui, from Sun Yat-sen University, China. "This means that
parents and others who manage children's time should encourage them to spend
time outdoors daily. When that's impractical due to weather or other factors,
use of daylight-spectrum indoor lights should be considered as a way to