## **Core Concept**
The sixth cranial nerve, also known as the **abducens nerve**, is responsible for the motor innervation of the **lateral rectus muscle**. This muscle is crucial for the outward movement (abduction) of the eyeball. A sixth nerve palsy leads to weakness of the lateral rectus muscle, causing difficulties in moving the affected eye outward.

## **Why the Correct Answer is Right**
A left-sided sixth nerve palsy affects the left lateral rectus muscle, leading to an inability to properly abduct the left eye. This results in **esotropia** (crossed eyes) of the left eye, particularly noticeable when trying to look sideways. The correct answer, , indicates that the left eye will be deviated medially (towards the nose) due to the unopposed action of the medial rectus muscle.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because a sixth nerve palsy does not lead to outward deviation of the eye; rather, it causes inward deviation due to the weakness of the lateral rectus muscle.
- **Option B:** This option is incorrect as it describes a situation more aligned with a medial rectus palsy or a different type of strabismus, not a sixth nerve palsy.
- **Option C:** This option might seem plausible but does not accurately describe the primary consequence of a sixth nerve palsy, which is an inability to abduct the eye.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that in a sixth nerve palsy, the affected eye may appear to be crossed or deviated inward, especially when attempting to look sideways. A common clinical test to assess for sixth nerve palsy is to ask the patient to look laterally; the affected eye will have difficulty moving outward.

## **Correct Answer:** . medial deviation of the left eye.