Eye Health

Conjunctivitis: Viral, Bacterial, or Allergic?

Red, gritty eyes could be viral, bacterial, or allergic. Differentiating the cause unlocks the right drops and tells you how contagious you are.

Written by the PharmacyConsultation.ie pharmacy team15 February 20269 min read
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INTRODUCTION

Introduction

Pink, watery eyes interfere with work, childcare, and driving. Most conjunctivitis cases resolve with supportive care, but the type—viral, bacterial, or allergic—dictates both treatment and contagion advice.

Pharmacists can triage the cause, supply medication, and flag any eye emergencies that cannot wait.

WHAT IS CONJUNCTIVITIS?

What Is Conjunctivitis?

Conjunctivitis is inflammation of the conjunctiva, the transparent membrane covering the white of your eyes and inner eyelids. Viral infections cause watery discharge, bacterial infections cause purulent discharge that mattes the eyelids, and allergic reactions cause intense itching with stringy mucus.

CAUSES & SYMPTOMS

Causes & Symptoms

Viral types often follow a head cold and spread rapidly through households. Bacterial types commonly follow hand-eye contact or contact lens issues. Allergic conjunctivitis peaks during pollen season or after exposure to dust and pet dander.

Key clues pharmacists look for:

  • Watery discharge and gritty sensation (viral)
  • Yellow/green discharge and lids stuck together in the morning (bacterial)
  • Intense itching, bilateral redness, and chemosis (allergic)
  • History of contact lens use, trauma, or chemical exposure

TREATMENT & PHARMACY SUPPORT

Treatment & Pharmacy Support

Simple viral cases need lubricating drops, saline rinses, and hygiene advice. Bacterial cases, once confirmed, respond to chloramphenicol or fusidic acid drops supplied via pharmacy protocols. Allergic conjunctivitis benefits from sodium cromoglicate or antihistamine drops plus oral antihistamines if nasal symptoms flare.

During your consultation you will learn:

  • How to instil eye drops without contaminating the bottle
  • How long each type remains contagious and when to return to work or school
  • When to remove contact lenses and how to disinfect cases properly
  • Why pain, light sensitivity, or vision change requires urgent escalation

RED FLAGS

Red Flags

Seek emergency eye care immediately if:

  • You develop true eye pain, visual disturbance, or halos around lights
  • Photophobia, corneal haze, or white spots on the cornea appear
  • Symptoms occur in a contact lens wearer or newborn
  • Eyelid swelling is severe or accompanied by fever (possible cellulitis)

PROTECT YOUR VISION

Protect Your Vision

Pop into your pharmacist at the first sign of pink eye. That quick assessment ensures you get the correct drops, proper hygiene advice, and immediate referral if something more serious is brewing.

Ready to feel better?

CCS pharmacists offer same-day triage, prescriptions, and safety-netting. Share a few symptoms online, pick a time, and collect treatment locally.

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This article is educational and is not a substitute for personalised medical advice. If you feel unwell, contact your pharmacist, GP, or emergency services.