Nearly 5 billion people to be short sighted by 2050

Half the world’s population will be myopic by the middle of the century, with up to one-fifth of them – about 1 billion people – at a significantly increased risk of blindness if current trends continue, a UNSW-led study shows.

The number of people with vision loss from high myopia is expected to increase seven-fold from 2000 to 2050, with myopia to become a leading cause of permanent blindness worldwide.

The study, by researchers at the Brien Holden Vision Institute at UNSW and the Singapore Eye Research Institute, is published in the journal Ophthalmology.

The authors attribute the rapid increase in the prevalence of myopia globally to “environmental factors, principally lifestyle changes resulting from a combination of decreased time outdoors and increased near work activities, among other factors".

The findings point to a major public health problem, with the authors suggesting that planning for comprehensive eye care services are needed to manage the rapid increase in high myopes (a five-fold increase from 2000), along with the development of treatments to control the progression of myopia and prevent people from becoming highly myopic.

“We also need to ensure our children receive a regular eye examination from an optometrist or ophthalmologist, preferably each year, so that preventative strategies can be employed if they are at risk,” says co-author Professor Kovin Naidoo, CEO of the Brien Holden Vision Institute.

“These strategies may include increased time outdoors and reduced time spent on near-based activities including electronic devices that require constant focussing up close.

“Furthermore there are other options such as specially designed spectacle lenses and contact lenses or drug interventions, but increased investment in research is needed to improve the efficacy and access of such interventions.”

Fact File

Myopia, also known as 'short-sightedness' or 'near-sightedness', causes people to have difficulty seeing distant objects clearly. It's estimated that there are currently 2 billion myopic people in the world, a figure that is growing rapidly.

The myopic eye is stronger than the non-myopic eye (often because the eye is longer). This means that instead of focusing on the back of the eye (the retina), light focuses in front of it, causing blurred vision.

• Myopia can be corrected by spectacles, contact lenses and refractive surgery
• Myopia usually begins in childhood at school age (six years and onwards) and can worsen until early adult years. This is referred to as youth-onset or juvenile-onset myopia. It can also occur in adults (ages 20 to 40) with no prior history of problems in childhood, termed early adult-onset myopia. One can also be born with high levels of myopia (congenital myopia)
• Myopia affects about 1 in 4 people in Australia, 1 in 3 in America and 1 in 2 in some Asian countries. In 2010, it affected more than a quarter of the world’s population
• The incidence of myopia has been rapidly increasing across the world. By 2020, it is estimated that the number of people with myopia will grow to one third of the world’s population (2.6 billion) and by 2050 there will be 4.8 billion myopes (around half the world's population)
• The causes of myopia are both genetic and environmental. It is suggested that increased urbanisation and close-range activities e.g. reading and computer work, are increasing the incidence of myopia
• Growing levels of high myopia are increasing the risks of serious eye conditions, such as myopic macular degeneration, cataract, glaucoma and retinal detachment, many of which may lead to permanent blindness
• It is predicted that by 2050 there will be almost 1 billion high myopes globally.