inflammation and infection of the lacrimal sac, usually stemming from obstruction of the flow of tears into the nose. Tears leave the eye through small openings called puncta in the inner corner of the eye and flow into the lacrimal, or tear, sac, from which they drain through a duct—the nasolacrimal duct—into the nasal cavity. Obstruction of the duct creates a stagnant collection of tears, which in turn leads to infection of the sac by bacteria such as staphylococcus or Streptococcus. Symptoms of dacryocystitis include tenderness, thick discharge, swelling, and redness over the inner corner of the lower eyelid near the nose. Treatment initially involves warm compresses and then, if necessary, antibiotics. Chronic dacryocystitis can lead to persistent tearing, recurrent infection, and scarring; surgical treatment may be necessary to reestablish tear flow into the nasal cavity.