Eye redness

A red or irritated eye is often not serious, but in some situations a red eye requires a quick medical consultation. If you notice a deterioration in your eyesight, you must seek urgent medical advice.

Red eyes do not necessarily mean that you are ill. It may be due to excessively rubbing your eyes, a lack of sleep, dry eyes, a cold, wearing contact lenses, prolonged exposure to a screen, the sun or an irritant (soap, dust, swimming pool chlorine, smoke).

In addition to these causes, the most common reasons for “red eye” are conjunctivitis and subconjunctival haemorrhage.

The conjunctiva is a thin, damp and transparent membrane which allows the eyelids to slide over the eye. It covers the internal side of the eyelids and the front part of the eye. Conjunctivitis is an inflammation of this membrane, for example due to bacteria or an allergy.

The symptoms of infectious conjunctivitis include eye redness, a prickling sensation, a sandy feeling in the eyes, watering and sometimes secretions which may make the eyes stick together, particularly at night. To prevent conjunctivitis spreading from one eye to the other, you have to avoid touching your eyes and wash your hands regularly.

Allergic conjunctivitis is present in people who suffer from an allergy, such as hay fever. In this case, the two eyes are normally affected. A cold with a blocked nose and sneezing is also often present.

A subconjunctival haemorrhage involves bleeding (a spot) behind the eye’s conjunctiva. It may happen for no reason or be caused by a considerable cough or sneeze. Even though the redness may look worrying, it is often harmless.


Eye redness has a wide range of causes. As such, treatment will depend on the diagnosis.

If it is just common redness caused by fatigue, the sun or a small irritation, try to rest your eyes, wear sunglasses and avoid screens for a little while. If you got soap, dust or another irritant in your eye, you can rinse your eyes with water or with small containers of liquid called “artificial tears”.

Infectious conjunctivitis can be treated with a warm water compress 3 times a day and by taking antibiotic drops (Hexamidine or Tobramycin) until symptoms have disappeared.


Some cases require medical assessment: if you sustained an impact to the eye, are in significant pain or are having eyesight problems or headaches, you should go to a doctor quickly. If you wear contact lenses and you get a red eye, you need to see an ophthalmologist immediately.

For further information

On the Planète santé website you can find a page on conjunctivitis and on the Manuel Merck website there is a page about subconjunctival haemorrhage.


Start for free

Medical advice?

Do you need a consultation with a GP?