A little girl gets a visual examination at her school in Lima, Peru. UN photo

A staggering 2.2 billion people already suffer from eye conditions and visual impairment today, but the global need for eye care is set to increase “dramatically” with lack of exercise a key factor, the United Nations (UN) health agency said on Tuesday, unveiling its first ever report on vision across the world.

While welcoming recent successes in eliminating common conditions such as trachoma in eight countries, the World Health Organization (WHO) highlighted evidence indicating that eye problems are increasingly linked to lifestyle choices, including screen time.

Youngsters are among those at risk, WHO’s Dr. Alarcos Cieza told journalists in Geneva:

“In children, one of the factors that may influence the increased number of children with myopia is that children do not spend enough time outdoors. It is a trend that is already observed in some countries like in China,” she said. “But of course, it is a trend that we can predict in other countries if it is an everyday habit, especially with child populations.”

The problem with staying inside is that the lens in your eye rarely relaxes, WHO’s Dr. Stuart Keel explained.

“When you’re indoors, the lens inside your eyes is in a complete flex state, or it’s flexed but when you’re outside, it’s nice and relaxed.”

Pointing to recent scientific data from China investigating the “clear link” between time spent outdoors and the delayed onset of later stage shortsightedness, Keel cautioned that studies on “near-task” activities such as watching video on a tablet computer, were “not as conclusive at this stage.”

According to the WHO’s World Report on Vision, the burden of impairment tends to be greater in low and middle-income countries.

Women also suffer disproportionately, along with migrants, indigenous peoples, and those with disabilities and rural communities.

“Eye conditions and vision impairment are widespread, and far too often they still go untreated,” said Dr. Tedros Adhanom Ghebreyesus, WHO Director-General. “It is unacceptable that 65 million people are blind or have impaired sight when their vision could have been corrected overnight with a cataract operation, or that over 800 million struggle in everyday activities because they lack access to a pair of glasses.”

Population growth and ageing — along with lifestyle changes and urbanization — will also “dramatically increase” the number of people with eye conditions, vision impairment and blindness in the coming decades, WHO’s report shows.

One of the study’s main findings is that prevention is key, since at least one billion people are living with sight problems that could have been avoided with timely treatment.