# Trachoma: symptoms, causes and treatment > Source: World Aid Network — https://worldaidnetwork.org/eye-health/trachoma > Last reviewed: 2026-06-19 ## In short Trachoma is an eye infection caused by bacteria, and it is the world's leading infectious cause of blindness. It spreads easily in places with limited clean water and sanitation — through contact with the eyes and nose of an infected person, and by flies. Repeated infections, often beginning in childhood, scar the inside of the eyelid until the lashes turn inwards and scrape the eye, causing intense pain and, eventually, blindness. Almost all of this suffering is preventable. The World Health Organization's SAFE strategy — Surgery, Antibiotics, Facial cleanliness and Environmental improvement — can stop trachoma and is helping eliminate it country by country. Trachoma is a chronic bacterial eye infection caused by Chlamydia trachomatis. It is the world's leading infectious cause of blindness and the second leading preventable cause of blindness overall, after cataracts. The World Health Organization estimates that trachoma threatens the sight of 125 million people in 44 countries, that approximately 1.9 million people are already blind or visually impaired from trachoma, and that around 8 million people have trichiasis — the late-stage complication in which in-turned eyelashes scratch the cornea, causing irreversible scarring and blindness. Trachoma is a disease of poverty. It flourishes in communities without access to clean water, adequate sanitation and proper hygiene facilities. Though it has been eliminated from most high-income countries for over a century, it persists across sub-Saharan Africa, parts of South and South-East Asia, and other endemic regions. This guide answers the twenty most commonly searched questions about trachoma, drawing on WHO and NHS sources. ## At a glance - Cause: Bacterial eye infection - Global rank: #1 infectious cause of blindness - Spread by: Contact and flies; poor sanitation - WHO response: The SAFE strategy ## When to see a doctor - Red, itchy or irritated eyes, especially in young children in affected areas - Sticky discharge from the eyes - Swollen, sore eyelids - Eyelashes that turn inwards and rub on the eye (a late, sight-threatening sign needing surgery) - Eye pain or discomfort in bright light ## How trachoma causes blindness Trachoma infection — particularly repeated reinfection in childhood — causes chronic inflammation of the inner surface of the eyelid (conjunctiva). Over time, repeated episodes of infection cause scarring of the eyelid tissue (conjunctival scarring). As scarring progresses, the eyelid contracts and turns inward (entropion), causing the eyelashes to rub against the cornea with every blink — a condition called trichiasis. The constant abrasion of the eyelashes causes progressive corneal opacification (scarring), leading to visual impairment and eventually blindness. Blindness from trachoma is irreversible — the corneal scarring that develops from years of trichiasis cannot be cured by simple surgery. Prevention — through infection control and early trichiasis surgery before corneal scarring develops — is therefore critical. ## The SAFE strategy The WHO advocates the SAFE strategy for trachoma elimination: Surgery (for trichiasis — to correct in-turned eyelashes before corneal scarring occurs); Antibiotics (mass drug administration of azithromycin to endemic communities to reduce the burden of infection); Facial cleanliness (promoting face-washing, particularly in children, to disrupt transmission); and Environmental improvement (clean water supply, latrine construction and environmental hygiene to address the root causes of trachoma transmission). Azithromycin — donated by Pfizer through the International Trachoma Initiative — is distributed annually or bi-annually as mass drug administration (MDA) to entire endemic communities, regardless of whether individuals appear infected. A single oral dose eliminates active Chlamydia trachomatis infection and has driven dramatic reductions in trachoma prevalence in many countries. ## Trichiasis surgery Trichiasis surgery is a simple outpatient procedure that rotates the eyelid margin outward, correcting the in-turned position and preventing the lashes from abrading the cornea. It takes approximately 15 minutes under local anaesthetic and is performed by trained ophthalmic nurses or surgeons. It does not restore vision already lost to corneal scarring, but prevents further damage from occurring. Post-operative recurrence of trichiasis is a known problem and careful surgical technique and follow-up are important. The WHO target is to perform trichiasis surgery for all people who need it by 2030. This requires training sufficient surgical providers and reaching the most remote, underserved communities where trichiasis prevalence is highest. ## Trachoma and World Aid Network Trachoma is endemic in regions that include Indonesia and parts of South-East Asia — areas within World Aid Network's operational geography. WAN's first registered Charitable Object covers sight-restoring eye surgery for poor patients in Pakistan, Indonesia and Malaysia. Supporting trichiasis surgery, cataract operations and access to eye care directly aligns with this Object and prevents unnecessary blindness in communities that have no access to public eye services. A donation to World Aid Network directly funds the eye surgery and care that prevents and cures avoidable blindness — giving people back the ability to work, care for their families and live independently. ## Key takeaways - Trachoma is the world's leading infectious cause of blindness — caused by repeated Chlamydia trachomatis eye infections in communities without clean water and sanitation. - Around 1.9 million people are already blind or visually impaired from trachoma; approximately 8 million people have trichiasis (in-turned eyelashes) that will cause blindness without treatment. - The WHO's SAFE strategy (Surgery, Antibiotics, Facial cleanliness, Environmental improvement) is successfully eliminating trachoma — but progress is uneven and the most remote communities remain at high risk. - Mass azithromycin treatment (donated through the International Trachoma Initiative) reduces the community burden of infection. Trichiasis surgery — a simple 15-minute procedure — prevents blindness in individuals with in-turned eyelashes. - Trachoma blindness is entirely preventable. It is a disease of poverty — absent from wealthy countries for over a century but persisting wherever communities lack clean water and basic sanitation. ## Frequently asked questions ### What is trachoma? Trachoma is a chronic, contagious bacterial eye infection caused by Chlamydia trachomatis. Repeated infection causes cumulative scarring of the inner eyelid, eventually causing the eyelid to turn inward (entropion) and the eyelashes to scratch the cornea (trichiasis) — leading to irreversible corneal scarring and blindness. The WHO identifies trachoma as the world's leading infectious cause of blindness, affecting 125 million people in 44 endemic countries. ### What causes trachoma? Trachoma is caused by infection with the bacterium Chlamydia trachomatis — specifically serotypes A, B, Ba and C, which are adapted to infect the eye. Infection causes acute and then chronic inflammation of the conjunctiva (the lining of the eyelid). Repeated reinfection — especially during childhood — is necessary for the scarring sequence that ultimately leads to trichiasis and blindness. A single infection that resolves without reinfection is unlikely to cause permanent damage. ### How does trachoma spread? Trachoma spreads through direct or indirect contact with ocular or nasal secretions from an infected person. Children — who have the highest rates of active infection — are the primary reservoir of Chlamydia trachomatis in endemic communities. Transmission occurs through: direct eye-to-eye or eye-to-hand-to-eye contact; sharing of towels, cloths or handkerchiefs; and flies (Musca sorbens) that feed on ocular and nasal secretions and transfer bacteria between people. This is why facial cleanliness — particularly face-washing in children — is central to the SAFE strategy. ### What are the symptoms of trachoma? In early stages, trachoma causes: redness of the eyes (conjunctivitis); watering or discharge; photophobia (sensitivity to light); and eyelid swelling. In active disease, small, pale follicles appear on the inner surface of the upper eyelid — a characteristic appearance visible on examination. With repeated reinfection over years, conjunctival scarring develops. Late-stage trachoma (trichiasis) causes constant eye pain as in-turned lashes scratch the cornea — described as extremely painful, like having grit permanently in the eye. ### What is trichiasis? Trichiasis is the late, sight-threatening complication of trachoma in which scarring of the inner eyelid causes it to turn inward (entropion), bringing the eyelashes into contact with the cornea. With every blink — approximately 10,000 times per day — the lashes abrade the corneal surface, causing progressive corneal ulceration, opacification and, ultimately, blindness. Approximately 8 million people worldwide have trichiasis. Trichiasis surgery — a 15-minute outpatient procedure — can prevent this blindness if performed before significant corneal scarring has occurred. ### How is trachoma diagnosed? Trachoma is diagnosed clinically by trained eye health workers using the WHO simplified grading system, which identifies five grades: Trachomatous Inflammation–Follicular (TF); Trachomatous Inflammation–Intense (TI); Trachomatous Scarring (TS); Trachomatous Trichiasis (TT); and Corneal Opacity (CO). This grading is performed with a 2.5× loupe and a torch — equipment that does not require electricity or laboratory facilities, making community-level assessment feasible in remote settings. Laboratory confirmation (PCR or culture) is used in research and surveillance. ### How many people are affected by trachoma? According to the WHO: 125 million people live in areas endemic for trachoma; 1.9 million people are blind or visually impaired from trachoma; and approximately 8 million people have trichiasis requiring surgery to prevent blindness. Children aged 1–9 years have the highest rates of active infection. Women are disproportionately affected by trichiasis — two to three times more than men — thought to be due to their closer contact with infected young children during caregiving. ### Which countries are affected by trachoma? Trachoma remains endemic in 44 countries, primarily across sub-Saharan Africa (where the highest burden is found), parts of South and South-East Asia, the Middle East, Central Asia, and the Pacific Islands. In South-East Asia, Indonesia has historically had endemic trachoma in certain provinces. Globally, the highest-burden countries include Ethiopia, South Sudan, Niger, Mali, Nigeria, Chad, Sudan and Tanzania. Many countries have successfully eliminated trachoma as a public health problem following sustained SAFE implementation. ### What is the SAFE strategy for trachoma? The WHO's SAFE strategy is a comprehensive approach to trachoma elimination: S — Surgery for trichiasis (correcting in-turned eyelashes before corneal scarring becomes irreversible); A — Antibiotics (mass azithromycin administration to endemic communities to reduce the burden of active Chlamydia infection); F — Facial cleanliness (promoting regular face-washing in children to reduce person-to-person transmission); E — Environmental improvement (construction of latrines, provision of clean water and household environmental hygiene measures). All four components must be implemented together for durable elimination. ### How is trachoma treated with antibiotics? Mass drug administration (MDA) of azithromycin — a single oral dose — is used to reduce the community prevalence of active Chlamydia trachomatis infection in endemic districts. Azithromycin (brand name Zithromax) is donated by Pfizer through the International Trachoma Initiative (ITI) and distributed to all eligible community members regardless of infection status. MDA is conducted annually or bi-annually in districts with TF prevalence above 10% in children aged 1–9. Tetracycline eye ointment is an alternative where azithromycin is unavailable. ### What is trichiasis surgery? Trichiasis surgery is a simple, outpatient surgical procedure that corrects the in-turned eyelid margin to prevent lashes from abrading the cornea. The most widely used technique is the Bilamellar Tarsal Rotation (BLTR) procedure: a full-thickness incision is made through the eyelid parallel to the lid margin; the outer portion is rotated outward and sutured, everting the eyelid margin and repositioning the lashes away from the eye. The procedure takes approximately 15 minutes under local anaesthetic and can be performed by trained ophthalmic nurses in community settings. ### Can trachoma be cured? Active trachoma infection — the inflammatory stage — can be cured with azithromycin. Trichiasis (in-turned eyelashes) can be corrected with surgery, preventing further corneal damage. However, corneal scarring that has already occurred cannot be reversed by any of these interventions — sight lost to corneal opacification cannot be restored without a corneal transplant, which is largely unavailable in endemic settings. This is why prevention and early treatment — before corneal scarring develops — are so critical. ### Can trachoma be prevented? Yes. Trachoma is entirely preventable at the individual and community level. The SAFE strategy addresses both personal and environmental risk: face-washing in children (particularly cleaning the face and eyes) disrupts person-to-person transmission; clean water access enables hygiene practices; latrine construction reduces fly breeding (Musca sorbens breeds in human faeces); and antibiotic MDA reduces community infection levels. Many countries have successfully eliminated trachoma through sustained SAFE implementation — demonstrating that elimination is achievable. ### Is trachoma linked to poverty? Trachoma is one of the classic 'diseases of poverty'. It thrives wherever communities lack: access to clean water (for face-washing); adequate sanitation (latrines — absence of which creates fly breeding grounds); and basic primary health care for early treatment of infections. Trachoma was eliminated from the United Kingdom and other high-income countries over a century ago, not through antibiotics or specific trachoma programmes, but through improvements in water supply, sanitation and living standards. Poverty is not just a risk factor for trachoma — it is its primary cause. ### Does trachoma affect children more than adults? Yes. Active trachoma infection — characterised by conjunctival inflammation and follicles — is most prevalent in children aged 1–9 years, who are the primary reservoir of Chlamydia trachomatis infection in endemic communities. Children become repeatedly reinfected throughout childhood, accumulating the conjunctival scarring that leads to trichiasis in adulthood. Adults — particularly adult women who have the most contact with infected children — bear the burden of trichiasis and trachomatous blindness. Blindness typically develops in middle age after decades of repeated infection. ### Why are women more affected by trichiasis than men? Women develop trichiasis and trachomatous blindness at approximately two to three times the rate of men in most endemic communities. This is attributed to their greater exposure to Chlamydia trachomatis through close caregiving contact with young children — who carry the highest levels of active infection. Repeated reinfection through this caregiving role accelerates conjunctival scarring in women relative to men in the same community. Targeted trichiasis surgery outreach to women is an important priority in national trachoma elimination programmes. ### What is the WHO target for trachoma elimination? The WHO has set targets for trachoma elimination as a public health problem: TF prevalence in children aged 1–9 years below 5% in all districts; trichiasis prevalence (unknown to the health system) below 0.2% in adults; and functional district-level capacity to manage incident trichiasis cases. As of recent WHO reports, 11 countries have been validated as having eliminated trachoma as a public health problem. The WHO aims to achieve global elimination, with the goal of 'GET2030' — global elimination of trachoma by 2030. ### Is trachoma found in the UK? Trachoma was common in the UK during the nineteenth century, particularly among poor urban communities in industrial cities. It was eliminated through improvements in water supply, sanitation and living standards long before antibiotic treatment became available — demonstrating that environmental and hygiene improvements are central to elimination. Today, trachoma in the UK is extremely rare and occurs only as imported cases in people who have lived in or visited endemic regions. It is not considered an endemic disease in the UK. ### Can trachoma come back after treatment? Yes. Mass azithromycin treatment reduces the community burden of active infection but does not provide lasting immunity against reinfection. Communities in endemic areas are susceptible to reinfection from surrounding villages or districts, making repeated annual MDA necessary until community prevalence falls below the elimination threshold. Post-treatment surveillance is essential to detect resurgence. Trichiasis surgery is also associated with recurrence in approximately 20–40% of operated eyes at five years — an ongoing challenge in trachoma programmes. ### How does World Aid Network help people affected by trachoma and other eye diseases? World Aid Network's first registered Charitable Object covers sight-restoring eye surgery for poor patients in Pakistan, Indonesia and Malaysia — countries within or adjacent to trachoma-endemic regions. WAN funds cataract operations, trichiasis surgery and eye care through locally-licensed ophthalmologists and registered hospitals, working with trusted local partner organisations that have deep community reach. A donation to World Aid Network directly funds the surgery and care that prevents and cures avoidable blindness — giving people back their independence, livelihood and quality of life. ## How you can help World Aid Network funds sight-restoring eye care for poor patients in Pakistan, Indonesia and Malaysia through locally-licensed surgeons. Donate at https://worldaidnetwork.org/donate --- This is general information, not medical advice, published by World Aid Network. Always consult a qualified clinician about your own health.