Refractive error may result in lost education and employment opportunities, lower productivity and impaired quality of life.
Uncorrected refractive errors, which affect persons of all ages and ethnic groups, are the main cause of vision loss worldwide.
In 2020, it was estimated that 157 million people had significant vision impairment (< 6/18 in the better eye) due to uncorrected refractive errors affecting distance vision, including at least three million people with blindness (< 3/60 in the better eye). In addition, 510 million people were without adequate correction for functional presbyopia in 2020.
The large majority of vision impairment in school aged children is due to uncorrected refractive error (Resnikoff et al., 2008).
The global economic cost in lost productivity due to avoidable distance vision impairment alone was estimated to be I$269 billion (approximately US$202 billion) each year in 2009
Presbyopia is the most common cause of vision impairment globally.
More than half of those requiring near-vision spectacles globally cannot access them. This is due to factors such as poverty, isolation, poor availability, poor access to eye health facilities and lack of awareness.
The 2020 Vision Loss Expert Group data estimates that in 2020 510 million people had presenting functional presbyopia, or blurred near vision.
As discussed in the Lancet Global Health Commission on Global Eye Health, data on effective coverage of refractive error will become increasingly available. Effective Refractive Error Coverage (eREC) was proposed and a methodology described (WHO World Report on Vision, 2019, McCormick et al., 2020).
The eREC assesses the proportion of people with refractive error who have received and use refractive error correction that achieves a specified VA threshold (e.g. 6/12); it takes into consideration the met, under-met and unmet refractive error need in a population.
This represents a major shift in the way refractive error is reported. Surveys previously focused only on counting unmet need (uncorrected refractive error) and excluded those who already had access to refractive error correction.