**Core Concept**
Refractive errors in the eye can be congenital or acquired. At birth, the eye is still developing, and any refractive errors present at this stage are usually due to anatomical or physiological abnormalities.

**Why the Correct Answer is Right**
The correct answer refers to a congenital condition where the cornea and lens of the eye are not properly formed, leading to a refractive error. This condition is often due to the incomplete closure of the embryonic fissure during fetal development. The resulting underdevelopment of the posterior segment can cause a significant refractive error.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify a refractive error present at birth.
**Option B:** This option is incorrect as it refers to an acquired condition, which develops later in life.
**Option C:** This option is incorrect as it is a type of refractive error, but it is not a congenital condition.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that refractive errors present at birth are often due to anatomical or physiological abnormalities, and a thorough ophthalmological examination is necessary to diagnose and manage these conditions.

**Correct Answer: C. Congenital Megalocornea.**