Conjunctivitis otherwise known as pinkeye, is an inflam-mation of the conjunctiva. It may be localized in either the palpebral conjunctiva or bulbar conjunctiva. Individuals may present with relatively nonspecific symptoms and signs that include redness, irritation, and watery discharge from the eye (Fig. F24.4.1). The symptoms can also mimic a foreign body sensation. Extended use of contact lenses can cause an allergic or bacterial conjunctivitis and may be the first sign of more serious ocular disease (i.e., corneal ulcer). In general, symptoms that last less than 4 weeks are classified as acute conjunctivitis, and those extending for a longer period are referred to as chronic conjunctivitis. Acute conjunctivitis is most commonly caused by bac-teria; a variety of viruses including HIV, varicella-zoster virus (VZV), and herpes simplex virus (HSV); or allergic reac-tions. Bacterial conjunctivitis often shows an opaque puru-lent discharge containing white cells and desquamated epithelial cells. On eye examination, the purulent discharge and conjunctival papillae help to differentiate between bac-terial and viral etiology. Viral conjunctivitis is most common in adults. Clinically, it presents as a diffuse pinkness of the conjunctiva with particularly numerous lymphoid follicles on the palpebral conjunctiva, often accompanied by en-larged preauricular lymph nodes. Viral conjunctivitis is very contagious and usually associated with a recent upper res-piratory infection. Patients need to be advised to avoid touching their eyes, to wash their hands frequently, and to avoid sharing towels and washcloths. Bacterial conjunctivitis is usually treated with antibiotic eye drops or ointments. For viral etiology, no antimicrobials therapy is needed. However, conservative management with artificial tears to keep the eye lubricated may relieve symptoms. Although there is no cure for viral conjunctivitis, symp-tomatic relief may be achieved with warm compresses and artificial tears. For the worst cases, topical corticos-teroid drops may be prescribed to reduce the discomfort of inflammation. However, prolonged use of corticos-teroid drops increases the risk of side effects. Antibiotic drops may also be used for treatment of complementary infections. Viral conjunctivitis usually resolves within 3 weeks. However, in worst cases it may take more than a month. FIGURE F24.4.1 • Conjunctivitis. This photograph of the lower part of the eyeball with reflected lower eyelid shows an infected conjunctiva. The enlarged blood vessels of the conjunctiva are responsible for moderate redness of the eye with conjunctival swelling. Frequently moderate, clear (in allergic conjunctivitis) or purulent (in bacterial conjunctivitis) discharge is visible. (Courtesy of Dr. Renzo A. Zaldivar.)
About 25 tarsal glands are present in the upper  eyelid, and 20 are present in the lower eyelid. The sebaceous secretion of the tarsal glands produces an oily layer on the surface of the tear film that retards the evaporation of the normal tear layer. Blockage of the tarsal gland secretion leads to chalazion (tarsal gland lipogranuloma), an inflammation of the tarsal gland. It presents as a painless cyst usually on the upper eyelid that disappears after a few months without any therapeutic intervention.
 Sebaceous glands of eyelashes (glands of Zeis) are small, modified sebaceous glands that are connected with and empty their secretion into the follicles of the eyelashes. Bacterial infection of these sebaceous glands causes a stye (also called hordeolum), a painful tenderness and redness of the affected area of the eyelid.