Red eye syndrome
A red eye is a symptom, not a diagnosis. Redness can be caused by dryness, allergy, subconjunctival hemorrhage, eyelid inflammation, episcleritis or scleritis, uveitis, acute angle-closure glaucoma, trauma or a foreign body, and other conditions.
It is not always conjunctivitis, which this page covers further down — and dryness of the eye surface is another common cause, which we cover in more detail in our article on dry eye syndrome.
When it is urgent
Seek urgent care if redness is accompanied by:
- pain;
- vision loss;
- light sensitivity;
- one-sided worsening;
- nausea or headache;
- symptoms that do not improve within 1–2 days.
Why self-treatment can be risky
Decongestant “whitening” drops may mask symptoms and worsen rebound redness or dryness. Proper treatment depends on the underlying cause.
The same symptom can require entirely different treatment. Only an ophthalmologist can determine the right approach for you.
Diagnosis in clinic
We begin with medical history and basic tests (vision, refraction, eye pressure), followed by slit-lamp examination and, when needed, a dilated evaluation.
Conjunctivitis
Conjunctivitis is inflammation of the conjunctiva. Symptoms include redness, discomfort, tearing, and sometimes discharge. Causes include viral, bacterial, allergic, and irritative factors (such as dry air, smoke, or chemicals).
Viral vs bacterial
- Viral: watery discharge and a gritty sensation, often with cold symptoms; usually managed with supportive care.
- Bacterial: thicker yellow or green discharge, eyelids stuck together in the morning; may require antibiotic drops or ointment, but only if clinically indicated.
Why diagnosis matters
Different types may appear similar but require different management.
Examination
History and vision assessment, eye pressure measurement if needed, and slit-lamp evaluation of the conjunctiva, cornea, and anterior chamber.
Key advice
- Avoid sharing towels or cosmetics.
- Wash hands frequently.
- Avoid decongestant drops.
- Wear contact lenses only as advised.
