**Core Concept**
Elschnig pearls refer to small, rounded collections of lens epithelial cells that can be seen at the edges of a mature posterior capsular cataract. This phenomenon is a result of the lens epithelial cells attempting to proliferate and form a new lens capsule.

**Why the Correct Answer is Right**
The Elschnig pearls form due to the proliferation of lens epithelial cells at the edges of the posterior capsular cataract. This proliferation is a result of the lens epithelial cells attempting to regenerate and form a new lens capsule in response to the opacification of the posterior capsule. The cells accumulate and form small, rounded collections, which are known as Elschnig pearls.

**Why Each Wrong Option is Incorrect**
**Option A:** Elschnig pearls are not seen in the context of anterior capsular cataracts. They are specific to posterior capsular cataracts.
**Option B:** Elschnig pearls are not related to the formation of snowflake cataracts, which are a type of immature cataract that forms in the lens cortex.
**Option C:** Elschnig pearls are not seen in the context of secondary glaucoma, which can be a complication of cataract surgery.

**Clinical Pearl / High-Yield Fact**
Elschnig pearls are an important clinical finding that can be seen in the context of mature posterior capsular cataracts. Recognizing this finding can help clinicians to better understand the pathophysiology of the cataract and to develop targeted treatment plans.

**Correct Answer: C. Elschnig pearls are seen in mature posterior capsular cataracts.**