Photo credit: Melvin Rodriguez

Uncorrected refractive error is the most common cause of vision impairment, and the second leading cause of blindness in the world. It is caused when the shape of the eye keeps light from focusing correctly, and means you require glasses, contact lenses, or surgery to see.

In 2021, member states of the World Health Assembly endorsed the first ever global target for increasing access to these interventions for refractive error. The target was developed around effective refractive error coverage (eREC), the proportion of people who have refractive error and have received treatment for it with a good outcome.

Countries have been encouraged to adopt national targets aligned with the global target of a 40 percentage-point increase by 2030.

To assess progress towards this goal, estimates of eREC are needed. A new study including ICEH researchers has revealed estimates for the indicator in 76 countries over the last two decades, and modelled estimates through to 2030.

The Vision Loss Expert Group (a global group of eye specialists and researchers) analysed data from 237 population-based eye surveys conducted in the countries since 2000, which included information from 815,273 people. Studies were from around the world. A map of the data sources is below:

Many of the surveys used were from the Rapid Assessment of Avoidable Blindness (RAAB), a methodology managed by ICEH.

eREC values reported from surveys varied widely globally, ranging from 2.1% in a RAAB study from Uganda (2023) to 94.0% in a comprehensive study done in France (2009–11).

Overall, global eREC was estimated to be 65.8% in 2023, a 6 percent increase from 2010. There were marked differences in eREC between regions (based on GBD super-regions) in 2023, ranging from 84% in high-income countries to 28·3% in sub-Saharan Africa.

In all super-regions, eREC was lower in women than men, and decreased with increasing age among adults aged ≥50 years.

The researchers also selected 16 most populous countries to demonstrate expected versus target eREC in 2030, finding that none are on track to achieve the eREC target set by the 74th World Health Assembly.

For example, in Bangladesh there is still a need to increase eREC by around 37 percentage points from 2023 values to 2030. High-income countries, such as the USA, already have a relatively high eREC with smaller percentage-point increases required, but need to strengthen efforts to reach underserved populations to achieve these.

The steady increase in global eREC is to be welcomed, but there is a need for acceleration to meet the 2030 targets.
Increasing eREC when the number of people with refractive error is increasing requires a major paradigm shift in how services are delivered. Global efforts to address refractive error include the WHO SPECS 2030 Initiative (since 2024), the Clear Vision Coalition (since 2019), and the ATscale partnership (since 2018).

The authors note several ways that countries can prioritise these issues, for example social entrepreneurship models, task shifting, and integration of technology. They also mention potential solutions to specific challenges, for instance using female eye-care workers to increase comfort and uptake among women and reduce gender disparity.

Correction of refractive error is the safest, most efficient, and most economical intervention to improve daily vision quality for the majority of individuals affected by vision impairment worldwide, contributing to the achievement of five SDGs: reducing poverty and improvements in well-being, work productivity, education, and equity. This analysis serves as an important update on our progress towards 2030 and the targets endorsed by WHO member states.

Publication

Bourne R, Cicinelli M, Selby D, Sedighi T, Tapply I, McCormick I et al. Effective refractive error coverage in adults: a systematic review and meta-analysis of updated estimates from population-based surveys in 76 countries modelling the path towards the 2030 global target. The Lancet Global Health. May 2025. https://doi.org/10.1016/S2214-109X(25)00194-9