What is the term for a small abscess on a hair follicle located on the eyelid?

The term for a small abscess on a hair follicle located on the eyelid is hordeolum. A hordeolum, commonly known as a stye, occurs when a gland near the hair follicle of an eyelash becomes infected or inflamed, leading to localized swelling and tenderness. The condition can often be seen as a red, painful bump at the edge of the eyelid, which is characteristic of this type of abscess.

The other terms listed refer to different eye conditions: a pterygium is a growth of tissue on the conjunctiva; a pinguecula is a yellowish, elevated lesion on the conjunctiva, typically associated with UV exposure; and ptosis refers to the drooping of the upper eyelid. Each of these conditions is distinct from a hordeolum in etiology and presentation, reaffirming the specificity of the term for identifying small abscesses of the eyelid.