Global blindness is a major public health problem. Worldwide, approximately 37 million people are blind, and an estimated 124 million have significant visual impairment.1 Home to 90% of blind individuals, developing countries bear a major burden of the condition. Seventy-five percent of cases of blindness are caused by cataract, trachoma, onchocerciasis, childhood blindness (xerophthalmia), and refractive errors that can be cured or prevented by available cost-effective interventions.2 In industrialized nations, such as the United States, the major cause of blindness is age-related macular degeneration, contributing to more than 50% of cases of blindness.3 Recent estimates by the World Health Organization (WHO) show that nearly 153 million people have significant vision impairment from uncorrected refractive errors (not including presbyopia).
Chandra SR. Global BlindnessVISION 2020: The Right to Sight. Arch Ophthalmol. 2008;126(10):1457. doi:10.1001/archopht.126.10.1457