**Core Concept**
Pterygium is a benign growth on the conjunctiva of the eye, typically occurring on the nasal side. It is often associated with chronic exposure to UV radiation and high humidity. The growth is thought to arise from the conjunctival epithelium, but its exact pathogenesis is still unclear.

**Why the Correct Answer is Right**
The correct answer is "Arise from any part of conjunctiva" because pterygium typically originates from the conjunctival tissue near the limbus, the border between the cornea and the sclera. While it can grow onto the cornea, its primary origin is from the conjunctival tissue, not any random part of the conjunctiva.

**Why Each Wrong Option is Incorrect**
**Option B:** Pterygium can indeed cause astigmatism due to the invasion of the cornea by the pterygium, leading to irregular curvature of the cornea.

**Option C:** While surgery is a treatment option for pterygium, it is not always the treatment of choice. In some cases, pterygium can be managed with observation, and surgery is reserved for symptomatic cases or those causing significant astigmatism.

**Option D:** UV exposure is a well-established risk factor for the development of pterygium, particularly in individuals with prolonged outdoor exposure.

**Clinical Pearl / High-Yield Fact**
A key clinical correlation to remember is that pterygium is more common in individuals with a history of chronic UV exposure, such as farmers, fishermen, and people living near the equator. This is because UV radiation is thought to play a role in the initiation and progression of pterygium.

**✓ Correct Answer: A. Arise from any part of conjunctiva**