Rural areas of low-resource countries bear the biggest burden of vision impairment from presbyopia, according to a new study in Ophthalmology. The investigators also reported the global unmet need for presbyopia correction in 2015 was estimated to be 45%.

Researchers performed systematic reviews of presbyopia prevalence and spectacle-correction coverage from data gathered into five-year age cohorts from birth to age 90 or older, and analyzed it within World Health Organization global burden of disease regions. They developed a model based on amplitude of accommodation adjusted for myopia rates to match the regionally analyzed presbyopia prevalence. Presbyopia spectacle-correction coverage was analyzed against country-level variables from the year of data collection.

The investigators estimated there were 1.8 billion people, globally, with presbyopia in 2015, 826 million of whom had near vision impairment because they had no, or inadequate, vision correction.

“People with presbyopia are more likely to have adequate optical correction if they live in an urban area of a more developed country with higher health expenditure and lower inequality,” researchers said.