Symptom

Red eye

Painful red eye needs urgent care

Clinically reviewed · Last reviewed 2026-06-13

When to get urgent help

  • A red eye with moderate or severe eye pain
  • Sensitivity to light or changes in your vision
  • A red eye after an injury or chemical splash
  • Intense redness with a headache, nausea or halos around lights

Common causes

Most red eyes are harmless. These are common causes, with the conditions to read about next.

Conjunctivitis Overview of pink eye — read viral, bacterial or allergic pages for your pattern. Viral conjunctivitis Watery red eye, often after a cold; very contagious. Bacterial conjunctivitis Sticky yellow-green discharge, lids glued on waking. Eye allergies Itchy, watery eyes in both eyes with hay-fever symptoms. Dry eye Red, gritty, tired eyes that may also water. Blepharitis Red, crusty eyelid margins and sore eyes. Subconjunctival haemorrhage A painless bright red patch from a burst vessel. Stye A red, tender lump on the eyelid. Uveitis A painful red eye with light sensitivity that needs prompt care. Corneal abrasion (scratched eye) A painful red eye after a scratch or foreign body. Acanthamoeba keratitis Severe pain with lens wear or water exposure; needs same-day care.

Types of pink eye

Viral conjunctivitis Very contagious watery pink eye, often after a cold; antibiotics do not help — hygiene and time are the main treatment. Bacterial conjunctivitis Sticky yellow-green discharge and glued lids, often needing antibiotic drops after assessment; more urgent in babies and contact-lens wearers. Eye allergies Itchy, red, watery eyes from pollen, dust or pets; seasonal peaks in spring and summer respond well to trigger avoidance and allergy drops.

What can help

  • Lubricating drops can ease redness from dryness or irritation
  • Gentle eyelid cleaning helps blepharitis and styes
  • See a clinician urgently if the eye is painful or vision changes

Frequently asked questions

When should I worry about a red eye?

Seek urgent care if a red eye comes with pain, light sensitivity, changes in vision, or follows an injury or chemical splash, as these can signal a more serious problem.

Is a red eye always conjunctivitis?

No. Conjunctivitis is common, but red eyes can also come from dry eye, blepharitis, a harmless burst blood vessel, or more serious causes such as uveitis.

How long does a red eye last?

Minor causes often settle within one to two weeks. A red eye that is painful, affects vision, or does not improve should be assessed.

Which pink eye type do I have?

Itch in both eyes with hay fever suggests allergy. Thick pus and glued lids suggest bacterial. Watery redness after a cold suggests viral. Read the matching conjunctivitis page for full guidance.

Is a bloodshot eye the same as pink eye?

Pink eye usually means conjunctivitis, but bloodshot eyes can also be dry eye, a burst vessel, blepharitis or more serious inflammation — pain or vision change needs assessment.