General Eye Conditions and Tests
What causes a red eye?
Most red eyes are caused by surface problems such as conjunctivitis, dryness, allergy or a burst surface blood vessel, and they are uncomfortable rather than painful, with normal vision. A red eye becomes urgent when there is real pain, reduced vision, marked light sensitivity or a contact lens involved, which can mean inflammation inside the eye, raised pressure or a corneal ulcer.
Common and generally harmless causes
- Viral conjunctivitis, with watery discharge, often starting in one eye and spreading, sometimes with a cold
- Bacterial conjunctivitis, with yellow sticky discharge and lids gummed together in the morning
- Allergic conjunctivitis, with itching, swelling and watering in both eyes
- Dry eye and blepharitis, with burning and grittiness
- A subconjunctival haemorrhage, a painless patch of bright blood on the white of the eye that clears over one to three weeks
Serious causes
- Corneal ulcer or infection, particularly in contact lens wearers, causing pain, light sensitivity and reduced vision
- Uveitis, inflammation inside the eye, with aching pain, light sensitivity and blurring
- Acute angle closure glaucoma, with severe pain, haloes, blurred vision, headache and sometimes vomiting
- Scleritis, a deep boring pain that may wake you at night
- Injury, foreign body or chemical splash
Practical advice
For infective conjunctivitis, wash hands frequently, use separate towels and avoid sharing bedding, since it spreads easily. Do not wear contact lenses while an eye is red. Cool compresses and lubricants ease irritation. Avoid drops that whiten the eye, and never use leftover steroid drops, which can turn a minor infection into a sight threatening one.
When to seek urgent assessment
- Significant pain rather than irritation
- Reduced vision or marked sensitivity to light
- A red eye in a contact lens wearer, which needs same day assessment
- A white or grey spot visible on the cornea
- A red eye after injury or a chemical splash, which needs immediate irrigation and emergency care
Frequently asked questions
- How long should conjunctivitis take to settle?
- Viral conjunctivitis often takes one to two weeks and can worsen before improving. Have it reviewed if vision drops, pain develops, or it is not settling after about ten days.
- Do I need antibiotic drops?
- Many cases are viral or allergic, where antibiotics do nothing. Treatment should follow examination rather than be assumed.
Concerned about these symptoms?
Arrange an eye examination with our consultant ophthalmologist in Garki, Abuja.
Related answers
- What does eye pain mean?
- What does discharge from the eye mean?
- Why are my eyes itchy?
- Why am I sensitive to light?
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