Featured Research

from universities, journals, and other organizations

Outdoor Activity And Nearsightedness In Children

Date:
August 5, 2008
Source:
American Academy of Ophthalmology
Summary:
A growing number of the world's children are mildly to severely nearsighted (myopic), with rates especially high among urbanized East Asians. In addition to coping with poor distance vision, children with severe myopia are more prone to visual impairment and blindness later in life.

A growing number of the world's children are mildly to severely nearsighted (myopic), with rates especially high among urbanized East Asians. In addition to coping with poor distance vision, children with severe myopia are more prone to visual impairment and blindness later in life.

Although genetic inheritance plays a role, the rapid rise of myopia suggests that environmental factors are driving the trend. Myopia usually begins and progresses during children's school years, but research on the role of intensive reading or other "near work" has determined that this is a minor factor. A new study led by Kathryn A. Rose, MD, used data from the Sydney Myopia Study of more than 4,000 Australian school children to assess whether outdoor activity might be significant in controlling myopia.

Parents and their children, at age 6 or 12, reported on the children's daily activities, which were classified as indoor or outdoor, and as near, medium or distance. Myopic refractive error, if any, was diagnosed for parents and children, and the children's ethnicity was recorded. A key finding was that the lowest myopia rates in 12-year-olds were associated with high outdoor activity, independent of the level of near work activity.

In 12-year-old students myopia was most strongly associated with high levels of near work and low levels of outdoor activity. The findings suggest that it is the time spent outdoors rather than engagement in sports that is critical; the association between increased outdoor hours and lower myopia was found even if an outdoor sport was not included, while time spent on indoor sports, such as playing basketball in a gym, had no effect.

The researchers think the intensity of outdoor light may be an important factor. Myopic eyes are longer, measured front-to-back, than normal eyes; in response to intense light, the retina releases dopamine, a neurotransmitter that inhibits eye growth and may thus influence the development of myopia. Also, the pupils of the eyes constrict in intense outdoor light, which increases the visual depth of field, the distance at which objects can be clearly seen.

The researchers recommend further study to prove conclusively whether certain levels of time spent outdoors can control myopia and to define the mechanisms involved. The higher exposure to intense outdoor light may explain the lower prevalence of myopia in children in Australia, compared with ethnically matched peers in other countries, Dr. Rose says. She adds that "this protective effect suggests that a public health measure aimed at preventing development of myopia could be based on increasing the engagement of children in outdoor activity," including family and school activities and sports.

This research was published in the August issue of Ophthalmology.


Story Source:

The above story is based on materials provided by American Academy of Ophthalmology. Note: Materials may be edited for content and length.


Cite This Page:

American Academy of Ophthalmology. "Outdoor Activity And Nearsightedness In Children." ScienceDaily. ScienceDaily, 5 August 2008. <www.sciencedaily.com/releases/2008/08/080801155221.htm>.
American Academy of Ophthalmology. (2008, August 5). Outdoor Activity And Nearsightedness In Children. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2008/08/080801155221.htm
American Academy of Ophthalmology. "Outdoor Activity And Nearsightedness In Children." ScienceDaily. www.sciencedaily.com/releases/2008/08/080801155221.htm (accessed August 21, 2014).

Share This




More Health & Medicine News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Possible Ebola Patient in Isolation at California Hospital

Possible Ebola Patient in Isolation at California Hospital

Reuters - US Online Video (Aug. 20, 2014) — A patient who may have been exposed to the Ebola virus is in isolation at the Kaiser Permanente South Sacramento Medical Center. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Raw: World's Oldest Man Lives in Japan

Raw: World's Oldest Man Lives in Japan

AP (Aug. 20, 2014) — A 111-year-old Japanese was certified as the world's oldest man by Guinness World Records on Wednesday. Sakari Momoi, a native of Fukushima in northern Japan, was given a certificate at a hospital in Tokyo. (Aug. 20) Video provided by AP
Powered by NewsLook.com
Do More Wedding Guests Make A Happier Marriage?

Do More Wedding Guests Make A Happier Marriage?

Newsy (Aug. 20, 2014) — A new study found couples who had at least 150 guests at their weddings were more likely to report being happy in their marriages. Video provided by Newsy
Powered by NewsLook.com
Ebola-Hit Sierra Leone's Freetown a City on Edge

Ebola-Hit Sierra Leone's Freetown a City on Edge

AFP (Aug. 19, 2014) — Residents of Sierra Leone's capital voice their fears as the Ebola virus sweeps through west Africa. Duration: 00:56 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins