‘Red eye’ is a general term used to describe an increased redness of the white part of the eye, often accompanied by irritation or pain and inflammation.

A red eye is usually caused by irritation of the front surface of the eye or inflammation within the front chamber of the eye. This can have many potential causes including bacteria, virus, allergy, a foreign body such as grit, an injury, dryness etc.


Bacterial conjunctivitis is the most common cause of a red eye, and will normally sort its self out in a few weeks, but sometimes needs some help with prescription antibiotic eye drops.

Conjunctivitis is generally not sight threatening; however it can be very contagious and is usually passed through flannels, towels, pillow cases.

If you have Conjunctivitis it is advisable to ensure you do not share any of these items with anyone.


Viral conjunctivitis can be caused by many different viruses including flu, COVID-19 and cold sore (herpes). In many cases no treatment is necessary, however some cases will require prescription of anti-viral or steroid eye drops.

Vial conjunctivitis can be very contagious so you should avoid sharing pillows and towels and always practice good hand hygiene.


Your eye can become red and irritated by common items such as cleaning products, air fresheners, cosmetics, animals, dust, or mould spores.

Allergic conjunctivitis can also be seasonal (hay fever). Although there is no cure for this, a systematic approach to finding the source can be time well spent and in cases of true allergy antihistamine tablets and eye drops may be recommended.

Additional comfort can be provided with lubricating tear drops to help keep the front surface of the eye hydrated.


Decent quality tears ensuring that the front of your eye does not dry out. Tears are made up of many chemicals in a delicate balance and if this is disturbed then the eye can become dry, gritty, sore, and tired.

There are many different lubricating tear drops (known as artificial tears or tear supplements) which are often used several times a day.

In more severe cases, a simple drainage plug, or minor surgical procedure can be used to reduce tear drainage – more information can be found on these treatments in our oculoplastics leaflet.


A foreign body in the eye is simply something that has entered the front of your eye that should not be there. Examples of these include a spec of dirt/grit, an eye lash, or a stuck contact lens. The eye will quickly become red and irritated.

It is important to try not to rub the eye as this may cause the object to scratch the front surface of the eye and make it much worse. Try to see if you can flush it out with a saline eye wash. Larger foreign bodies are normally removed painlessly, in a clinic, with an eye drop of local anaesthetic.

Then it can be found with a special microscope and removed. Deeply embedded foreign bodies, or those that have gone into the eye itself, will require a same-day referral to Eye Casualty for further treatment.


Blepharitis is an inflammation of the eye lids and is often caused by the oil glands at the base of the eye lashes becoming clogged or infected.

This can usually be treated with hot compresses, eyelid cleaning treatments and eyelid massage, available over the counter.


Contact lens wearers are prone to more serious eye infections which can cause rapid sight loss, especially if the lenses are not replaced each day, slept in, not kept clean or exposed to water which is not sterile.

If you are a contact lens wearer with a sudden onset red eye, then please seek urgent care at Eye Casualty or call our urgent care line on 0800 112 0070.

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