Viruses or localised infections can cause the eye to redden.

Whether it’s a lack of sleep or swimming in a chlorinated pool, it’s usually obvious why your eyes are giving you trouble. But sometimes what seems a routine annoyance could point to a deeper problem. Here are potential causes of your eye symptoms


Cold sore: Viruses or localised infections can cause the eye to redden – the problem usually starts in one eye, but can spread to both. Other symptoms of an eye infection include throbbing pain around your eye, sensitivity to light (photophobia) and a watery eye. You may need antiviral drops or ointment from your GP. If you have a cold sore on your mouth, always wash your hands after touching it.

Iritis: If the eye turns a deep red and you have throbbing pain at the front, this could be iritis or anterior uveitis – inflammation of the iris. This is triggered by an over-reaction of the immune system, though its exact cause isn’t known. The redness tends to start at the centre of the eye and spreads in a red ring around the centre within 24 to 48 hours. Treatment initially involves corticosteroid eye drops, though if there is infection you may need antibiotics.

High blood pressure: Persistent red blotches on the whites of both eyes can be a sign of hypertension, explains Ian Grierson, professor of ophthalmology at the University of Liverpool. High pressure causes the blood vessels to expand or even burst, leaving red marks across the white of the eye (but not the coloured part).

Haemorrhage: If one eye suddenly becomes red without any other symptoms, then it could be a subconjunctival haemorrhage – where blood leaks in the thin layer of skin at the front of the eyeball. This is very common, particularly in older people. It can be brought on by a violent coughing fit, vomiting, or if you are prone to nose bleeds or bruising. It should clear up by itself within a couple of weeks.


The menopause: This causes changes in hormone levels, affecting, among other things, the lubrication mechanisms of the eye, says David Allamby, an ophthalmic surgeon and medical director of the Focus Laser Eye Clinic in London. There is less fluid for the tear film which washes over the surface of the eye – so leading to dry eyes.

To tackle the problem, close your eyes for 20 seconds every 10 minutes, suggests James Ball, consultant ophthalmic surgeon at St James’s Hospital in Leeds.

Working in an air-conditioned office or leaving contact lenses in for too long can also cause dry eyes.

Most eye drops contain preservatives to inhibit bacteria because they are used again and again.

Eye drops without preservatives come in one-dose tubes – once they’re opened, they should be used up or thrown away after one day. As well as using eye drops, dry eyes can be helped by taking a supplement of omega 3, 6 and 9.

Sjogren’s syndrome: An auto-immune condition affecting around half a million people in the UK, this causes the body to attack its own moisture-producing glands, leading to abnormal dryness of the eyes, says Allamby.

Other symptoms include extreme dry mouth and muscle fatigue. The slow-onset condition affects women more than men, and is typically diagnosed in your 40s and 50s. The symptoms can be eased with artificial tears.

Exposure keratitis: Here the cornea, the dome at the front of the eye, has become dry. It can be caused by not closing the eyes properly during sleep.

Other causes include injury to the eye or not blinking enough, which leads to dryness of the cornea. Treat with artificial tears.


Blepharitis: This is an irritation and infection of the skin of the inner eye lids, and affects millions of people. Sometimes flakes appear on the eyelids which look like dandruff, but are actually flakes of skin from the eyelid.

It can be caused by a bacterial infection but is also associated with rosacea, a skin condition which causes the face to redden, explains Robert Scott, consultant ophthalmologist at the NHS Birmingham and Midland Eye Centre in the UK.

There’s no cure for blepharitis – Scott advises treating it by putting a tiny pinch of bicarbonate of soda in a cup of hot water, dipping in a cotton wool bud and then running this along the eye lash margin. Do this twice a day to reduce irritation.

Allergy: Itchy eyes are often a symptom of allergies, a problem known as allergic conjunctivitis.

There are two types: seasonal allergic conjunctivitis (which typically happens because of exposure to grass, pollen, trees and weeds), and perennial allergic conjunctivitis (which happens all year long due to exposure to household allergens such as mould, dust and pet hair). Symptoms may subside when away from the cause. Antihistamines and steroid nasal sprays can often control the eye symptoms.


High cholesterol: A milky-white ring around the iris can be a sign of high cholesterol.

Known as arcus senilis, this white ring is caused by the deposition of fat in the cornea, the clear area at the front of the eye, explains ophthalmic surgeon Oliver Backhouse, of the Yorkshire Eye Hospital. The ring should disappear with treatment and lifestyle changes. Not everyone with high cholesterol will develop this symptom.

Wilson’s disease: A coppery-coloured ring round the eye can be a sign of Wilson’s disease, a rare genetic disorder which causes too much copper to build up in the body. Untreated, it can cause damage to the liver and brain.

Treatment is through medication and avoiding foods with a high concentration of copper such as liver, chocolate, nuts and mushrooms.


Blocked tear ducts: If the tear ducts are blocked, this means fluid can’t drain away.

As the fluid stagnates, it can lead to infection and a sticky discharge in the duct, making the eyes water.

You may also develop a painful swelling on the side of the nose next to the eye.

The problem is more common with age, because collagen – a protein in skin – can shrink within the tear duct, blocking it off, says Allamby. It can also be caused by a cold. If the problem is caused by a chronic blockage, a common option is surgery.


Scratch to the eye: A corneal abrasion causes a very sharp pain and instinctively the eyelid will close to protect the cornea from bright light. These kinds of injury usually heal by themselves, although antibiotic eye drops can prevent further infection.

Ulcer: A corneal ulcer can cause a sharp, constant pain in the eye but also make the brightness of the eye look dull. The ulcer itself can look like a speck of cottage cheese.

It is important to get help quickly – treatment involves antibiotic drops or steroids – to avoid damage.

Glaucoma: A deep-boring pain can be a sign of glaucoma, which occurs when the eye’s drainage tubes become blocked.

Left untreated it can lead to blindness. Drugs such as prostaglandin analogues increase the flow of fluid out of your eye, while beta blockers can reduce fluid production. – Daily Mail