Bacterial conjunctivitis

What it is

Bacterial conjunctivitis is infection or heavy bacterial overgrowth on the clear surface of the eye. Common bacteria include Staphylococcus and Streptococcus species. It is contagious through hand-to-eye contact and shared towels.

Symptoms

Discharge texture helps distinguish bacterial from viral or allergic causes.

• Thick yellow-green pus, especially on waking
• Eyelids stuck together in the morning
• Red, gritty eye — may start one side then both
• Mild discomfort rather than severe pain in simple cases
• No dominant itch (unlike allergy)

Who needs prompt assessment

Most adults can be assessed within a day or two, but same-day care is important for:

• Newborns or infants under 4 weeks with red or sticky eyes
• Contact-lens wearers — remove lenses and seek advice the same day
• Moderate to severe eye pain or light sensitivity
• Reduced vision or a pupil that looks abnormal
• Redness after eye injury or surgery

Treatment

Hygiene reduces spread: wash hands, avoid sharing towels, discard used tissues, and stop contact lenses until cleared. Antibiotic drops or ointment are often prescribed for 5–7 days — finish the course unless advised otherwise. Lubricating drops can wash away discharge between doses. Read the antibiotic eye drops guide for technique.

School, work and contagion

You are usually most contagious while the eye is actively red and discharging. Many schools and workplaces accept return once antibiotic treatment has started and discharge is improving — follow local public-health guidance. Viral conjunctivitis is often more contagious for longer; bacterial disease typically improves faster with treatment.

When to seek urgent care

Emergency assessment for severe pain, marked light sensitivity, halos, nausea, or reduced vision — these suggest corneal ulcer, glaucoma or deeper infection, not simple conjunctivitis.