**Core Concept**
Trachoma is a bacterial infection caused by Chlamydia trachomatis, leading to chronic conjunctivitis and potentially causing blindness. Screening for trachoma is crucial in endemic areas to prevent its progression.

**Why the Correct Answer is Right**
Trachoma screening is primarily focused on children, as the disease can cause severe complications if left untreated. The World Health Organization recommends conducting trachoma screenings in children aged 1-9 years, as they are more susceptible to the disease. This age group is also critical for identifying cases that can be treated and prevented from progressing to more severe stages.

**Why Each Wrong Option is Incorrect**
**Option A:** Children under 1 year are not typically screened for trachoma, as they are less likely to be infected and the disease is often asymptomatic in this age group.
**Option B:** Adults are not the primary focus of trachoma screening, although they may be tested if they have been in close contact with infected individuals or if they have a history of the disease.
**Option C:** Older adults (those over 60 years) are not typically screened for trachoma, as the disease is less common in this age group and other eye conditions are more prevalent.

**Clinical Pearl / High-Yield Fact**
The AFT (Active Case Finding and Treatment) strategy is a recommended approach for trachoma control, focusing on identifying and treating cases in children aged 1-9 years and their family members.

**Correct Answer: C. Children aged 1-9 years.**