Bad conjunctivitis: what to know

Conjunctivitis inflames the thin surface covering the eye and eyelids. Viral, bacterial, and allergic forms can all cause redness, watering, irritation, or discharge, but their patterns differ. Eye discharge may make the eyelids stick together, particularly after sleep. Itching often points towards an allergic pattern, while a gritty feeling can occur with irritation or infection.

Severe eye pain, strong light sensitivity, reduced vision, a cloudy-looking eye, or swelling around the eye is not typical of mild surface irritation. Contact lens wearers need prompt advice for a painful or very red eye because the cornea can also be affected.

Wash hands before and after touching the eye, clean discharge with clean damp cotton or gauze, and avoid rubbing. Do not share towels, pillows, cosmetics, or eye drops. Pause contact lens use until a clinician advises that it is safe, and discard eye products that may have been contaminated. A GP consultation can help distinguish likely causes; antibiotic treatment is useful only when a clinician considers a bacterial infection likely.

Seek urgent eye care for vision loss or change, severe pain, pronounced light sensitivity, injury, chemical exposure, a bulging eye, or rapidly increasing swelling. Contact a clinician promptly if symptoms are severe, one eye is much worse, discharge is heavy, or a contact lens is involved. Keep chemical-exposure advice in mind: rinse the eye with clean running water while arranging emergency help.

Does the pattern suggest viral, bacterial, allergic, or another eye problem? Should I use drops, and for how long? When can I return to contact lenses, work, school, or shared activities?