This document discusses blinding trachoma, an infectious disease that can cause blindness. It notes that a community with blinding trachoma can be identified by the presence of lesions like trichiasis and corneal ulcers in some individuals. The document states that non-blinding trachoma can progress to blinding trachoma when other eye pathogens interact and increase the risk of vision loss. Environmental factors that can increase the risk of trachoma transmission and progression include seasonal increases in eye-seeking flies during warmer months, poor living conditions associated with poverty and crowding, and customs like applying kajal or surma to the eyes.

3. • A community with blinding trachoma can be
recognized by the presence of persons with lesions
such as enfropion, trichiasis and corneal ulcers.
• It is the blinding trachoma that requires urgent
control measures.
• Non-blinding trachoma often becomes blinding
trachoma when other ocular pathogens interact
synergistically and enhance the risk of damage to
eye sight

17. Environmental factors
• (a) SEASON · Seasonal epidemics are associated with
vastly increased number of eye-seeking flies. The
incidence of active trachoma is found generally high in
India during April-May and again during July-September.
The higher temperature and rainfall favours the increase
in fly population.
• (b) QUALITY OF LIFE: Trachoma is associated with poor
quality of life. The disease thrives in conditions of
poverty, crowding, ignorance, poor personal hygiene,
squalor, illiteracy and poor housing. As living conditions
improve the disease tends to regress.
• (c) CUSTOMS : The custom of applying kajal or surma to
the eyes is a positive risk factor.