Blepharitis is chronic or long-term inflammation of the eyelids and eyelashes that affects people of all ages. Causes include poor eyelid hygiene, excessive oil produced by the glands in the eyelid, bacterial infection (often staphylococcal), or an allergic reaction.

Symptoms are greasy flakes or scales around the base of the eyelashes and a mild redness of the eyelid or a roughness of the normally smooth tissue that lines the inside of the eyelid. In many cases, good eyelid hygiene and a regular cleaning routine may control blepharitis.