Entropion is characterized by:

Entropion is a medical condition that specifically involves the inward turning of the eyelid. This abnormal position of the eyelid can cause the eyelashes and skin to rub against the cornea, leading to discomfort, irritation, and potential damage to the eye itself. The inward turning may occur in one or both eyelids and is often associated with aging, scarring, or muscle dysfunction.

The other options refer to different conditions: turning outward of the eyelid describes ectropion, absence of the lens signifies aphakia, and increased intraocular pressure is characteristic of glaucoma. Understanding the specific definition of entropion is crucial for correct diagnosis and subsequent treatment. Thus, recognizing that entropion refers to the eyelid turning inward helps to clearly delineate it from other ocular conditions.