The Ophthalmology Unit,  Universiti Malaysia Sarawak (UNIMAS), Kuching, Sarawak.

The Ophthalmology Department, Sarawak General Hospital, Kuching, Sarawak, East Malaysia.



Hering's law of innervation as applied to ptosis

Photo by Professor Chua Chung Nen

This 68 year-old man presented with a two-year history of right ptosis and lower lid entropion. The ptosis was of the involutional type. By elevating the right ptosis, the left eyelid became ptotic (Hering's law of equal innervation) indicating that he had bilateral ptosis being worse in the right than left side. Therefore, ptosis surgery was performed for both eyes to avoid post-operative left ptosis.


Right involutional ptosis and lower lid entropion. The left corneal reflex is visible.


By elevating the right upper eyelid, the left lid becomes ptotic and the corneal reflex disappears.

A large upper eyelid abscess resulted from infected eyebrow follicle.

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