Avoidable blindness: the main causes in the world and in Colombia
- Topic
Most visual impairment in the world could be prevented or treated: glasses and cataract surgery alone would restore sight to many millions.
What it is
The World Health Organization estimates that at least 2.2 billion people live with a near or distance vision impairment, and in at least 1 billion of them it could have been prevented or has not yet been addressed. The leading causes are uncorrected refractive error and cataract, both treatable with low-cost interventions. Glaucoma, diabetic retinopathy, macular degeneration, corneal opacity and trachoma follow. Access, cost and awareness, not lack of treatments, keep people blind.
Key facts
- Leading cause of vision impairment worldwide: uncorrected refractive error.
- Leading cause of blindness worldwide: cataract.
- Other causes: glaucoma, diabetic retinopathy, age-related macular degeneration, corneal opacity, trachoma.
- Children: refractive error, amblyopia, congenital cataract, retinopathy of prematurity, vitamin A deficiency.
- Colombia was the first country certified by WHO as free of onchocerciasis transmission.
In clinical practice
- The general doctor prevents blindness by screening (red reflex, acuity, diabetic retina, glaucoma suspicion) and by completing referrals.
- Diabetes and population ageing are increasing the burden of retinal disease and glaucoma.
- WHO promotes integrated, people-centred eye care within primary health care.
Next step / Initial management
- Check visual acuity at every health check where it is due and refer by criteria.
- Make sure people with cataract that limits daily life reach surgery.
- Screen diabetic patients' retinas and children's eyes on schedule.
- Prescribe and help obtain glasses: the cheapest effective eye intervention.
Test yourself
Think of the answer, then tap the question to see it.
What is the leading cause of blindness worldwide?
Cataract.
What is the leading cause of vision impairment worldwide?
Uncorrected refractive error.
Which eye-related public health milestone did Colombia reach first?
It was the first country certified by WHO as having eliminated onchocerciasis transmission.
Connections
Educational content; not a clinical guideline and no substitute for assessment by a health professional. For sudden visual loss, severe eye pain, a chemical burn or an eye injury, go to an emergency department at once.
Sources: World report on vision (World Health Organization, 2019); Blindness and vision impairment: fact sheet (World Health Organization, 2023); Onchocerciasis: fact sheet (World Health Organization, 2022).
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Representative model, for educational purposes only.