Bacterial conjunctivitis is much less common than viral or allergic conjunctivitis in adults. Children and people with chronic ocular conditions tend to be more prone to bacterial conjunctivitis.

Patients will typically complain of ocular irritation, redness, foreign body sensation, and tearing associated with increased discharge. Itching is less common in bacterial conjunctivitis.

Inoculation of the conjunctiva is usually by direct hand-eye contact or can be due to direct spread of organisms located in the patient's own nasal passageway or sinuses. Often, patients will have concurrent sinus disease, upper respiratory infection (URI), or infectious dacryocystitis (infection of the lacrimal sac).

The onset of symptoms is usually over days to weeks but can be as short as 24 hours (hyperacute) or as long as years (chronic conjunctivitis). Hyperacute conjunctivitis is typically caused by Neisseria gonorrhoeae, and chronic conjunctivitis is typically caused by Chlamydia trachomatis or Staphylococcus associated with blepharitis. Acute forms of bacterial conjunctivitis are the most common manifestations associated with the diagnosis.

Note: As of August 25, 2023, the US Food and Drug Administration is reminding the public that these recalled products should not be used due to potential bacterial contamination: EzriCare Artificial Tears, Delsam Pharma Artificial Tears, and Delsam Pharma Artificial Ointment.