Why is one eye suddenly smaller than the other?

If one eye suddenly appears smaller than the other, it could be due to a condition called ptosis. Ptosis occurs when the upper eyelid droops lower than normal, giving the affected eye a smaller appearance. This can develop suddenly and may affect vision if the drooping eyelid covers part of the pupil.

There are several potential causes of sudden ptosis, including:

• Muscle weakness: Conditions like myasthenia gravis can affect the muscles that control the eyelid, leading to drooping. This can happen after birth or later in life.
• Nerve damage: Nerve issues, such as those caused by a stroke or a brain tumor, can affect the eyelid’s muscles, causing one eye to droop.
• Local eye problems: Infections or trauma to the eye or surrounding tissues can also lead to a drooping eyelid.
• Aging: In some cases, ptosis can develop with age as the muscles that lift the eyelid weaken over time.
• Medications: Certain medications, such as botulinum treatment (e.g., Botox) can cause ptosis as a side effect.

If you notice this symptom, especially if it develops suddenly, it’s important to see a doctor for evaluation. Sudden ptosis can be a sign of an underlying medical issue that needs to be addressed. Treatment of ptosis depends on the cause, but may include surgery or medications.

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