Cataract is the leading cause of vision loss in the world. The World Health Organization (WHO) has estimated that more than 20 million people are blind due to cataract and that the condition causes 51% of blindness worldwide. The majority of cases (up to 90%) of blindness due to cataract are found in developing areas. Cataract is also the leading cause of visual impairment, with 33% of the world’s population experiencing decreased vision because of this disorder; only refractive error has a greater impact in this regard.
Cataracts may be congenital, metabolic, age-related, or traumatic in origin. Cataracts affected 24.4 million individuals in the United States in 2015, and the Centers for Disease Control and Prevention (CDC) Vision Health Initiative estimates that this number is expected to rise to almost 40 million by 2025. Age-related cataracts are presumed to have the greatest socioeconomic impact because of their high prevalence. Congenital cataracts are responsible for 5%–20% of cases of blindness in children worldwide.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.