Understanding red eye – the symptoms, causes, and treatment
What is red eye?
A bloodshot ‘red eye’ may be worrying but is rarely serious or causes pain.
Symptoms often disappear within a few days, without treatment.
But if it does not improve within a few days, there may be a more serious problem.
Symptoms of red eye
You will need to see an eye specialist for a diagnosis and treatment, if you have:
- painful red eye
- other symptoms including reduced vision, sensitivity to light, or a severe headache and sickness
- recently had any injury to the eye – especially a blow with a sharp object
Common causes of red eye
With a painless red eye, the most likely causes are conjunctivitis or a burst blood vessel, which don’t usually affect the vision.
Conjunctivitis is inflammation of the conjunctiva, which is the thin layer of tissue covering the eyeball and inner surfaces of the eyelids.
The inflammation causes the blood vessels on the eye to become swollen, and a bloodshot look, along with a gritty feel.
There can be other symptoms with conjunctivitis – such as itchy eyes or watery eyes.
An eye specialist may recommend:
- regularly clean away any crusting or discharge around the eye
- temporarily stop using contact lenses until the eye is better
- washing your hands regularly and avoiding sharing pillows/towels to help prevent the spread of infection
- using antibiotic eye drops for bacterial infections of the eye or medications for allergies such as pollen
Burst blood vessel in the eye
A burst blood vessel on the eye surface can cause a bright red blotch called a subconjunctival haemorrhage. It can look alarming, but it’s not usually serious and should clear up on its own within a few weeks.
What causes painful red eye?
There are several possible reasons and they can be serious.
Iritis is inflammation of the iris (coloured part of the eye) – symptoms include red eye but there may be other symptoms such as sensitivity to light, blurred vision, or a headache. Treatment with steroid medication reduces the inflammation. Iritis rarely leads to any severe problems but see an eye specialist.
If your red eye is severe and painful, with nausea and seeing halos around lights, and your vision is blurred or cloudy, this may be acute glaucoma – a serious condition with a sudden increase in eye pressure and you must see an eye specialist immediately.
Corneal ulcer (ulcer on the cornea)
An ulcer on the cornea (the clear outer layer at the front of the eyeball) can cause the eye to become red and sensitive to light, with discomfort in your eye. Bacterial corneal ulcers are usually seen in people who wear contact lenses. Your ophthalmologist will advise on treatment.
A scratch to the cornea or particle in the eye
A particle in the eye can also cause a painful red eye. The best option is to go to an accident and emergency department.