**Core Concept**
The lens of the eye is a unique structure with a specialized epithelial layer, which plays a crucial role in its development and function. However, the lens epithelium is absent in a specific area, which is essential to understand for ophthalmological examinations.

**Why the Correct Answer is Right**
The lens epithelium is a single layer of cuboidal cells that covers the anterior (front) surface of the lens. However, the posterior (back) surface of the lens is devoid of epithelial cells. This absence of epithelium on the posterior surface is due to the lens's developmental process, where the posterior lens capsule forms from the lens vesicle without the overlying epithelial layer. This unique feature of the lens is essential to maintain its transparency and refractive power.

**Why Each Wrong Option is Incorrect**
**Option A:** The anterior surface of the lens does have a layer of epithelial cells, which are responsible for lens growth and maintenance. Therefore, this option is incorrect.

**Option C:** The anterior pole of the lens refers to its central portion, which does have a layer of epithelial cells. Thus, this option is incorrect.

**Option D:** Zonular attachment refers to the fibrous zonules that suspend the lens in the eye. The absence of epithelium is not related to the zonular attachment site, making this option incorrect.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that the lens epithelium is responsible for lens growth and maintenance, and its absence on the posterior surface is a unique feature that distinguishes the lens from other epithelial-lined structures in the body.

**✓ Correct Answer: B. Posterior surface**