**Core Concept:**
Angle of deviation, also known as the angle of misalignment, is the measure of the lateral displacement of an eye from its normal position. In infantile esotropia, this refers to the condition where the eyes are turned inward (esotropia) at rest or during near vision.

**Why the Correct Answer is Right:**
In infantile esotropia, the angle of deviation is typically greater than 10 degrees at near vision and less than 10 degrees at distance. The correct answer "D" represents the definition of the angle of deviation in this context, which is important in assessing and diagnosing the condition.

**Why Each Wrong Option is Incorrect:**
A. Option A is incorrect because it is the opposite of the actual angle present in infantile esotropia (eyes turning inward).
B. Option C is incorrect because it is a different condition (eyes turning outward, exotropia), and the question specifically asks about infantile esotropia.
C. Option B is incorrect as it is the opposite of the angle of deviation in infantile esotropia.

**Clinical Pearl / High-Yield Fact:**
Infantile esotropia is a type of strabismus (eye misalignment) that typically presents in children under 3 years old. Early diagnosis and management are crucial to prevent amblyopia (lazy eye) and to guide the eye muscles back to their normal alignment.

**Core Concept:**
Angle of deviation refers to the lateral displacement of an eye from its normal position. In infantile esotropia, the angle of deviation is greater than 10 degrees at near vision and less than 10 degrees at distance.

**Why the Correct Answer is Right:**
The correct answer "D" represents the definition of the angle of deviation in infantile esotropia, which is essential in assessing and diagnosing this condition accurately. The angle of deviation helps determine the severity of the misalignment, which guides treatment decisions.

**Why Each Wrong Option is Incorrect:**
A. Option A is incorrect because it represents the opposite angle of deviation (eyes turning outward) in exotropia, which is different from infantile esotropia.
B. Option C is incorrect as it refers to another type of strabismus (eye misalignment) called exotropia, where the eyes turn outward.
C. Option B is incorrect because it represents the opposite angle of deviation (eyes turning inward) in esotropia, which is different from infantile esotropia.

**Clinical Pearl / High-Yield Fact:**
Diagnosing and managing infantile esotropia require a thorough understanding of angle of deviation, as it contributes to treatment decisions and the prevention of amblyopia (lazy eye) development. Early diagnosis and intervention are crucial for optimal outcomes in these patients.