India needs to keep an eye on its myopia prevalence

Even though current estimates in the country do not reflect trends in the Asia-Pacific, India must be vigilant

Millions of young children are growing up short-sighted every year because of myopia. The World Health Organization (WHO) estimates that there were nearly two billion people with myopia in 2010 — a quarter of the human population. By 2030, they project myopia prevalence to reach 3.3 billion people. While East Asia and the Pacific have been reporting some of the highest numbers for a decade now, current estimates out of India do not yet reflect this trend. It may mean we have time to act and save the sight of our children.

Myopia is commonly found in children. As they grow and their bodies change, the length of the eyeball and its power to refract light do not always align, leading to vision that is blurry. A pair of spectacles is enough to correct this mismatch. However, spectacles address the symptom and not the cause (eyeball length), so myopia can progress all through childhood. Progressive myopia, after a point, leads to ‘high’ myopia, increasing the risk of retinal detachment, glaucoma or macular degeneration that can cause permanent vision loss.

A host of environmental and genetic factors determine the onset of myopia. It is believed that exposure to sunlight and a healthy balance between distance- and near-work can arrest myopia onset and progression. Many children, especially in urban environments, are spending more time indoors and on near-work. Be it at school or at home, the quantum of near-work — looking at books, television, phones or laptops — has increased over the decades. The COVID-19 pandemic has only accelerated this trend by robbing children of outdoor playtime and exposure to sunlight. This big shift to near-work seems to be triggering an increase in myopia prevalence.

Data from the East Asian countries have been particularly alarming. Even before the novel coronavirus pandemic, 80%-90% of high school children in East and Southeast Asia were presenting with myopia. Nearly 20% of them had high myopia. All these countries are racing to put in place systems to increase sunlight exposure and reduce near-work for children. The World Health Organization is warning of a global myopia epidemic, where millions of our children are at risk of vision impairment. Projections show nearly 50% of the world’s population will be myopic by 2050.

India seems to be bucking this trend. Current studies are recording low myopia prevalence among schoolchildren when compared to East Asia. In India, one in 30 to one in five schoolchildren are presenting with myopia. In a large study that surveyed 1.2 million schoolchildren in Telangana and parts of Andhra Pradesh, public health optometrist Winston Prakash and his team found myopia prevalence of a little over 5%. Even including those already with glasses, the prevalence numbers are low. What explains these anti-climactic numbers?

Despite a demographic shift towards cities and towns, nearly 65% of India’s population still lives in rural areas. As urbanisation increases, so does the burden of myopia. Myopia can be twice as high among urban children when compared to rural ones. One study found a higher prevalence among South Asian children in the United Kingdom compared to those living in rural India. So, it is likely that urban schools are harbingers of increasing myopia in children. Small studies are already finding that myopia prevalence in urban Indian schools is relatively higher, at nearly 35%. The spectacle power of urban children with myopia is also increasing year on year. Taking all these factors into account, prediction models are pointing to a myopia prevalence of nearly 50% in India too by 2050 — similar to global projections.

There are many treatment strategies to constrain myopic progression, including pharmaceuticals and specialty spectacles or contact lens. But like all public health issues, prevention strategies that tackle myopia onset and progression are far more inexpensive and cost-effective. We need to encourage parents to take children out to parks and other outdoor spaces regularly. Schools must ensure adequate exposure to sunlight. We need educational methodologies at every school level that balances near-work with distance-work.