How long allergic conjunctivitis lasts

A brief exposure, such as handling an animal and then touching the eyes, may cause a short flare that fades once contact stops and the eye surface settles. Ongoing exposure to pollen, dust mites, mould or workplace material can maintain inflammation, so redness, watering and itching may recur over days or through a season.

The timeline also depends on whether the trigger can be avoided, whether treatment is used correctly, and whether another condition is present. Dry eye, eyelid inflammation, infection and irritation from contact lenses can resemble allergy or occur alongside it, making symptoms appear unusually prolonged.

Reduce contact with the suspected trigger where practical. Wash your face and hair after outdoor exposure, change pollen-covered clothing, use a cool compress and avoid rubbing. Preservative-free lubricating drops may rinse the eye surface; a pharmacist or clinician can advise whether an allergy medicine is appropriate.

Take contact lenses out while the eye is inflamed. If medicine has been prescribed, use it on the recommended schedule rather than only when symptoms become intense, and learn the correct drop technique. Keeping a note of location, activity, season and associated nasal symptoms can reveal why episodes keep returning.

Arrange an examination when symptoms do not begin to settle with appropriate avoidance and treatment, repeatedly return, or remain one-sided. Thick discharge, eyelids stuck together or increasing swelling may indicate a cause other than a simple allergy.

Seek urgent care at any point for eye pain, blurred or reduced vision, pronounced sensitivity to light, injury, chemical exposure, or a red painful eye in a contact-lens wearer. These features matter regardless of how long the redness has been present.

Tell your clinician when each flare starts and stops, whether both eyes are involved, which exposures precede it and what treatments you have tried. Ask whether preventive treatment before a predictable season is suitable and whether allergy testing would identify a trigger you can meaningfully avoid.