Which condition involves the outward turning of the eyelid rim?

The condition that involves the outward turning of the eyelid rim is ectropion. This condition can occur when the eyelid loses its normal tone and support, leading to the eyelid margin turning outward, exposing the inner eyelid and potentially causing irritation or discomfort.

Ectropion can often result from various factors, including aging, trauma, or certain health conditions. It's important to differentiate this condition from others that affect the eyelids, such as entropion, which is characterized by the inward turning of the eyelid, making it rub against the eyeball. Conjunctivitis, often referred to as pink eye, is an inflammation of the conjunctiva and is not related to the structural position of the eyelid. Trichiasis involves eyelashes growing inward towards the eye rather than any outward turning of the eyelid itself. Understanding the distinction between these conditions is crucial for proper diagnosis and treatment.