MCQ Detailed View

The movement of the human eye is controlled by six muscles that work together to allow vision in multiple directions. These muscles are coordinated by three main cranial nerves: the oculomotor nerve (III), the trochlear nerve (IV), and the abducens nerve (VI). Damage to any of these nerves can affect eye movement, but the abducens nerve is specifically responsible for controlling outward eye movement.

The abducens nerve innervates the lateral rectus muscle, which moves the eye laterally (away from the nose). If this nerve is damaged due to injury, stroke, brain tumor, or nerve compression, the affected person may experience:

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  Inability to move the eye outward

  
  


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  Misalignment of the eyes (strabismus)

  
  


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  Double vision (diplopia)

  
  


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  Difficulty focusing on objects

  
  

The other nerves mentioned in the options have different functions:

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  Optic nerve (cranial nerve II): Responsible for transmitting visual information from the retina to the brain, not for moving the eye.

  
  


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  Trigeminal nerve (cranial nerve V): Supplies sensation to the face and controls chewing muscles but does not affect eye motion.

  
  


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  Abducens nerve (cranial nerve VI): Specifically controls the lateral rectus muscle, making it essential for proper horizontal eye movement.

  
  

Damage to the abducens nerve leads to a noticeable eye movement defect, where the affected eye cannot move fully to the side, resulting in double vision or abnormal positioning.

Thus, the correct answer is Abducens nerve, as it directly controls one of the primary muscles responsible for eye movement.