Which condition refers to the inflammation of the eyelid margins?

Blepharitis refers specifically to the inflammation of the eyelid margins. This condition can arise from various causes, including bacterial infections, seborrheic dermatitis, or allergies. Key symptoms typically associated with blepharitis include red, swollen eyelids, flaking skin at the base of the eyelashes, and an itchy or burning sensation. It can lead to crusting of the eyelids upon waking and may result in discomfort during blinking.

Conjunctivitis, on the other hand, involves inflammation of the conjunctiva, which is the clear membrane covering the white part of the eye and the inner eyelids. This often leads to redness, discharge, and irritation but does not specifically target the eyelid margins.

Keratitis is the inflammation of the cornea, usually associated with symptoms such as eye pain, reduced vision, and sensitivity to light, and it does not involve the eyelid margins.

Uveitis refers to inflammation of the uvea, which is the middle layer of the eye, and it can cause redness, pain, and visual disturbances, again not limited to the eyelid margins.

Thus, blepharitis specifically addresses the condition affecting the eyelid margins, making it the correct answer.