**Core Concept**
Subconjunctival cysts are localized, fluid-filled lesions beneath the conjunctival epithelium, often resulting from parasitic infection. Among parasitic diseases, cysticercosis is characterized by the presence of *Taenia solium* larvae, which can form cysts in various tissues, including the eye.

**Why the Correct Answer is Right**
In cysticercosis, the larval form of *Taenia solium* can migrate to the eye and form subconjunctival cysts. These cysts are typically painless, asymptomatic, and may be discovered incidentally. The cysts result from the parasitic larva's presence in the conjunctival tissue, leading to localized inflammation and cyst formation. This is a well-documented ocular manifestation of cysticercosis, especially in areas with poor sanitation or exposure to infected pork.

**Why Each Wrong Option is Incorrect**
Option A: Toxoplasmosis typically presents with retinal lesions, uveitis, and vitritis, not subconjunctival cysts. It causes granulomatous inflammation, not cystic formations.
Option C: Leishmaniasis causes granulomatous lesions in the eye, primarily involving the cornea and retina, with no association with subconjunctival cysts.
Option D: Chaga's disease (Chagas disease) affects the heart and digestive system, and while it can cause ocular complications, these are usually due to systemic involvement, not subconjunctival cysts.

**Clinical Pearl / High-Yield Fact**
Subconjunctival cysts are most commonly associated with cysticercosis, especially in endemic regions. If a patient has a history of travel or exposure to pork, and presents with a painless, asymptomatic ocular lesion, cysticercosis should be considered—especially when other causes are ruled out.

✓ Correct Answer: B. Cysticercosis