Red eye is a very common disorder. Dr Óscar Gris tells us what causes it and why self-medication can be harmful

Dr Óscar Gris, a cornea specialist at the IMO, tells us about the diseases that can cause red eye and how they should be dealt with

What is red eye?

Red eye is a condition in which the white of the eye turns red. It is often caused by an inflammation of the ocular surface, but sometimes the inflammation is inside the eye, which can be a symptom of a more serious disorder.

What are the most common causes of red eye?

Fortunately, most patients with red eye only have a mild inflammation on the surface of the eye, which can be caused by different disorders. The most common are conjunctivitis, dry eye syndrome and conditions associated with the use of contact lenses. Each cause has a specific treatment, which, in most cases, is highly effective: ConjunctivitisThere are different types of conjunctivitis, each of which has a specific treatment. Allergic and irritative conjunctivitis usually develop in the summer, as a result of using swimming pools and air conditioners, whereas bacterial and viral conjunctivitis can occur throughout the year and are usually associated with colds. Each type requires a certain treatment (antibiotics, anti-inflammatories, artificial tears, etc.), and it is important to know that treatment that works in some cases can be harmful in others. Dry eyeSome cases of red eye are caused by dry eye. It consists of a number of symptoms and sensations of discomfort resulting from poor lubrication of the ocular surface, either because the lacrimal fluid produced by the eye is insufficient or it is unstable and poor quality, characterised by excessively rapid evaporation. The sensation of dryness and itching usually diminishes when the eyes are closed. Most patients have mild dry eye and can control it easily with the occasional application of artificial tears (when using a computer or air conditioning, or in specific situations, in which they should receive treatment), while others need to use them continuously. Some treatments can be personalised according to the type of eye and patient comfort. Misuse of contact lenses: Misuse of contact lenses is a common cause of red eye. This can be due to excessive use, sleeping while wearing lenses, inadequate hygiene and also using them while bathing in the sea or a swimming pool. This is a fairly common practice, but not advisable, since the water may contain the Acanthamoeba parasite, which is a cellular organism that occasionally affects contact lens wearers and can cause a serious infection, especially if not treated in the first few days. The best thing to do to avoid risks is to always remove contact lenses before any kind of bathing.

When should you go to the ophthalmologist?

As a general rule, if there is no loss of vision or pain, patients should not worry too much. If it is just redness as a result of irritation, artificial tears without preservatives will usually alleviate the problem, and a visit to the ophthalmologist would only be necessary if it has not disappeared within 24 hours. If there is a loss of vision or pain, the red eye could be a symptom of a more serious corneal disorder, in which case the patient should go to see the ophthalmologist as a matter of urgency.

Precautions for healthy eyes during the summer

We should look after our eyes like we do after our skin: good hydration and protective measures against the harmful effects of the sun, chlorine, swimming pool disinfectants, etc. The main recommendations are:

  • Wearing sunglasses for prolonged exposure to the sun
  • Lubricating the eyes with artificial tears without preservatives, if dry eye occurs
  • Using goggles, if a long time is spent in the water, especially for children
  • Not wearing contact lenses while bathing to avoid complications that can become aggravated

Recommendations for red eye: do not self-medicate

It is becoming increasingly possible to tailor treatment to the needs of each individual patient, and even each eye, as they can evolve differently. The effectiveness of medication has improved greatly, but treatment that is appropriate in one case could be detrimental in another. Patients should, therefore, not self-medicate, but consult the experts instead. If, in addition to red eye, there is a general loss of vision, the patient should visit the ophthalmologist as a matter of urgency. Click here to listen to the full Onda Cero interview ("Pont Barcelona-Madrid", 16 July 2012, starting at 01:30).

You may be interested in