WHO fact sheet on blindness and visual impairment providing key facts, definitions, causes, who is at risk, global and WHO response.
Vision impairment and blindness impact the life of people everywhere. In low- and middle-income settings the burden of vision impairment can be even greater due to fewer opportunities to access the most essential eye care services.
Eye care, vision impairment and blindness programme Eye conditions are remarkably common and many eye conditions can lead to vision impairment, including blindness. Those who live long enough will experience at least one eye condition during their lifetime. Globally, at least 2.2 billion people have a vision impairment.
The World Health Organization (WHO) is urging countries to accelerate efforts to ensure that millions of people living with cataract can access simple, sight‑restoring surgery – one of the most effective and affordable interventions to prevent avoidable blindness.
One in two people facing cataract blindness need access to life ...
Night blindness (in which it is difficult or impossible to see in relatively low light) is one of the clinical signs of vitamin A deficiency, and is common during pregnancy in developing countries. Retinol is the main circulating form of vitamin A in blood and plasma.
Trachoma is a disease of the eye caused by infection with the bacterium Chlamydia trachomatis. It is a public health problem in 32 countries and is responsible for the blindness or visual impairment of about 1.9 million people.
Eye care, vision impairment and blindness: Refractive errors 11 February 2026 | Questions and answers