The axial length of eyeball at birth is ……………………… % of an adult eye –

**Core Concept**
The development of the eye involves significant changes in size and structure from birth to adulthood, including the axial length. The **axial length** of the eyeball is a crucial factor in determining the refractive power of the eye.

**Why the Correct Answer is Right**
At birth, the axial length of the eyeball is approximately 17-18 mm, which is about 60% of the average adult axial length, which is roughly 24 mm. This significant increase reflects the growth and development of the eye during childhood.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it underestimates the proportion of the adult axial length at birth.
**Option B:** This option overestimates the proportion, as the eye grows substantially after birth.
**Option D:** Similarly, this option suggests a value that is too high to be accurate.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that the eye continues to grow until early adolescence, and abnormalities in this growth can lead to refractive errors.

**Correct Answer:** C. 60%