India to change its definition of blindness to meet WHO criteria

The government is set to change a four-decade-old definition of blindness to bring it in line with the WHO criteria and ensure the Indian data on blindness meets the global estimates.

The World Health Organization (WHO) defines blindness as visual sharpness of less than 3/60, or a corresponding visual field loss to less than 10 degrees in the better eye, even with the best possible spectacle correction. The National Programme for Control of Blindness (NPCB) in India, on the other hand, defines blindness as vision of 6/60 or less and a visual field loss of 20 degrees or less in the better eye, after spectacle correction.

This means a person unable to count fingers from a distance of six metres is categorised as “blind” in India, against the WHO’s stipulation of three metres. This change in definition will bring down the number of blind persons by 4 million.

“With the NPCB definition, we will be addressing an extra four million individuals, blind due to refractive errors. By adopting the blindness criteria of WHO, India can achieve the vision 2020 goal,” said Dr Praveen Vashist, in-charge, community ophthalmology at Dr RP Centre for Ophthalmic Sciences at AIIMS.

Under Vision 2020, India has to reduce the prevalence of blindness to 0.3% of the total population. India projects a higher number of blind people at international fora due to its definition. India currently has around 12 million blind people against 39 million globally, which makes India home to one-third of the world’s blind population.

“We will bring the definition of blindness at par with WHO criteria,” said Promila Gupta, NPCB deputy director general.