What is ectropion?

Ectropion is a condition characterized by the turning out of the eyelid margins, specifically the lower eyelid. This involution can lead to various symptoms, including dryness, irritation, and excessive tearing, as the inner surface of the eyelid becomes exposed to the external environment.

The correct choice provides an accurate definition of ectropion, emphasizing the anatomical change in the eyelid structure, which can ultimately affect visual comfort and eye health. This condition is often due to aging, but it can also result from trauma, previous surgery, or neurological conditions.

The other options relate to different ocular conditions: progressive deterioration of the macula pertains to age-related macular degeneration, farsightedness refers to hyperopia, and a bacterial infection of an eyelash follicle describes a stye or hordeolum. None of these conditions involve the specific outward turning of the eyelid that defines ectropion. Thus, the selected answer captures the essence of the condition accurately and distinctly.