What causes bacterial conjunctivitis?

Bacterial conjunctivitis is inflammation and infection of the thin membrane over the white of the eye and inner eyelids. It commonly presents with red eyes, gritty discomfort, watering, and sticky eye discharge that may make the lashes cling together. Bacteria can transfer through hand-to-eye contact, shared towels, cosmetics, or respiratory secretions. Similar symptoms can also have viral, allergic, or eyelid-related causes, so discharge alone does not establish the cause. Light sensitivity, marked pain, or vision change is less typical and needs prompt assessment.

Wash hands before and after touching the eyes, avoid rubbing, and do not share towels, pillows, cosmetics, or eye drops. Gently clean discharge with clean water and a fresh pad for each eye. Pause contact lenses until a clinician confirms it is safe to resume, and replace or clean lens equipment as advised. A GP Consultation can distinguish likely causes and check the eye. Antibiotic Treatment may be prescribed when bacterial infection is suspected; use it exactly as directed and do not use someone else's medicine.

Arrange assessment if symptoms are worsening, fail to settle, recur, or affect a contact-lens wearer. Seek urgent eye care for significant pain, strong light sensitivity, reduced vision, injury, swelling around the eye, or inability to open the eye. These features may indicate a deeper eye problem rather than uncomplicated conjunctivitis.

Ask whether the pattern fits bacterial, viral, or allergic conjunctivitis, whether you should stay away from work or school, and when lenses or cosmetics can be used again. Ask how to apply drops safely and which warning signs require same-day review.