A red eye is common and usually does not cause vision problems.
Key points about red eye
- In most cases, a red eye is usually harmless although it can look serious.
- However, see your GP urgently if you have a red eye and blurry vision, eye pain, discharge from the eye, sensitivity to light, wear contact lens or have had an injury or trauma to your eye.
- Treatment of a red eye will be based on the condition you have.
- In most cases, a red eye will clear itself.
See your doctor urgently if you have a red eye on one or both sides and any of the following:
These symptoms suggest more serious causes and an urgent referral to an ophthalmologist (specialist eye doctor) may be needed.
What are the causes of a red eye?
A red eye is caused by the expansion of blood vessels on the white part of your eye, known as the sclera. This can be caused by a number of conditions, including:
- blepharitis (inflammation of your eyelids)
- keratitis (inflammation of your cornea)
- eye injury
- subconjunctival haemorrhage (burst blood vessels)
- environmental irritants such as dust, smoke, fumes and chemicals
- eye drops
- dry eye.
How is a red eye diagnosed?
You can see your doctor, optometrist or an ophthalmologist for a diagnosis. An optometrist is a trained healthcare provider who diagnoses and manages eye conditions. An ophthalmologist is a trained specialist doctor who manages eye conditions and performs eye surgery.
Your eye care provider will ask you about your symptoms, such as:
- whether you have a red eye on one side or both eyes
- how long have you had a red eye
- any change to vision, discharge, pain or sensitivity to light
- any recent injury to your eye
- other symptoms such as fever, headache, nausea or a rash
- whether you wear contact lenses
- whether you have had any recent contact with someone with a red eye.
They will also examine your eye and perform tests if necessary to find out the cause of your red eye. Read more about eye examination.
How is a red eye treated?
Treatment of a red eye will be based on the specific condition you have. for example, if you have conjunctivitis, the approach will be to treat your conjunctivitis, and may include antibiotic eye drops or ointments. Dry eye is treated with lubricating eye drops. Uveitis, episcleritis and scleritis are treated with anti-inflammatory eye drops. Subconjunctival haemorrhage will clear on its own.
Acute glaucoma is a potentially blinding condition. It requires urgent specialist input and treatment with medicine, laser and potentially surgery.
How can I care for myself if I have a red eye?
If you have a red eye, don't:
- wear contact lens until your symptoms get better
- touch or rub your eyes.
The following links provide further information about red eye. Be aware that websites from other countries may have information that differs from NZ recommendations.
- Red eye Auckland Regional HealthPathways, NZ, 2019
- Causes, complications and treatment of a red eye BPAC, NZ, 2013
- Red eye Patient Info, UK
- Evaluation of red eye BMJ Best Practice, UK
Dr Divya Perumal works at the Eye Institute and Auckland public hospital. She has expertise in performing eye surgery, including advanced glaucoma surgery and cataract surgery. She is a senior lecturer at the University of Auckland and is actively involved in teaching junior doctors and research, as well as conducting public lectures.