It's not watching too much television or playing computer games but spending too much time indoors that will ruin your child's eyes, according to a new study.
The five-year study by Sydney University researchers suggests children aged under six years should spend at least 10 hours a week outdoors in the sunshine to reduce their risk of becoming short-sighted or myopic.
Orthoptist Professor Kathryn Rose, head of the study, explained that exposure to direct sunlight at a young age helps prevent the eyeball from growing too fast and becoming oval or egg-shaped instead of round, News.com.au reported.
The researchers noted that prevention of myopia is important for future eye health because even low levels of the condition can create a higher risk of cataracts and glaucoma in adulthood.
The research, published in American journal Ophthalmology, also suggested that there is a "modern myopia epidemic" in countries where there is an emphasis on academic success at an early age, with levels of myopia in schoolchildren in countries like Singapore, Taiwan and Korea now between 80 and 90 per cent.
To this, Prof Rose suggested that schools should move classes outside to ensure kids were exposed to sunlight.