Our eyes perform constant and precise movements to allow us to focus and explore the world around us. These movements are made possible by a complex system of muscles and nerves that work in harmony. However, when one or more of these muscles are affected by paralysis or paresis, our visual ability can be seriously impaired.

Oculomotor paralysis refers to the inability or difficulty in performing one or more eye movements. This can occur as a result of an injury to the muscles that control eye movement or to the nerves that innervate them.

 

What are the symptoms of oculomotor paralysis?

The most common symptoms can vary depending on the affected cranial nerve and the severity of the condition. Below are some of the most common symptoms associated with this pathology:

  • Binocular diplopia: When both eyes are open, we experience double vision, which disappears when one eye is closed.
  • Strabismus: The eyes do not move together in the same direction, causing misalignment. The position will depend on the affected muscle or muscles.

    • Paralysis of the III cranial nerve: difficulty moving the eye upward, downward, and inward. As a result, the eye may be deviated outward (temporally). If the paralysis is complete, it can also cause mydriasis (dilation of the pupil) and ptosis (slight drooping of the eyelid compared to the other eye).

    • Paralysis of the IV cranial nerve: difficulty moving the eye downward and inward (nasally). Characteristically, it causes double vision when performing near-vision activities (reading, sewing, etc.). The eye may be deviated upward.

    • Paralysis of the VI cranial nerve: difficulty moving the eye outward (temporally). Characteristically, it causes double vision when looking at distant objects (looking out the window, driving, etc.). The eye may be deviated inward.

    • Ptosis: La parpella superior d’un ull cau més que l’altre.

    • Difficulty focusing: It may be difficult to focus on objects at close or far distances.

    • Blurred vision: Vision may be blurred or distorted.

    • Eye pain: In some cases, there may be eye pain or headaches.

    • Torticollis: To avoid double vision, some patients tilt their heads so that when looking straight ahead, their eyes are positioned in a way that requires the least deviation, thereby experiencing less diplopia.