Ophthalmological diseases

Here you can discover the most important eye diseases and we will help you to recognise their symptoms and tell you how each condition is treated.

Red eye

What is red eye?

The term red eye is used to describe redness of the eye caused by various eye diseases and ailments. It is a common condition and is the most frequent reason for visiting an ophthalmologist.
Red eye is caused by dilation and inflammation of the blood vessels in and around the eye, which causes redness of the sclera (white part) of the eye. Its presence is usually a sign of conditions affecting the parts of the eye behind the iris and lens, although most cases of red eye are not serious. In fact, the degree of redness does not tend to be related to the severity of the disease that causes it. However, diseases that cause red eye and impaired vision or eye pain can be serious.

 Healthy eye
Healthy eye
Red eye
Red eye


Red eye can be a symptom of various problems and conditions that cause irritation, dilation and inflammation of the blood vessels in the eye area:

  • Conjunctivitis: inflammation and redness of the blood vessels in the conjunctiva (the membrane that covers the white of the eye), which can be due to viral or bacterial infections, allergic reactions to pollen or other allergens such as mites or antibiotics, and irritative reactions to cosmetic or chemical products.
  • Keratitis: a disease that originates in the cornea (the dome-like structure at the front of the eye that covers the pupil and iris) when it becomes inflamed, causing redness, pain, tearing or acute intolerance to contact lenses, all of which affects vision.
  • Uveitis: inflammation of the uvea (the membrane between the retina and the sclera or white of the eye), which causes severe redness of the eye due to the high concentration of blood vessels in the area.
  • Dry eye: lack of eye lubrication caused by a reduction in the quality or quantity of tears, causing inflammation and redness of the eye.
  • Incorrect use of contact lenses: bathing with lenses in, not washing hands properly before handling them, exceeding the recommended number of hours of continuous use or sleeping with them in can cause eye irritation and redness.
  • Corneal ulcers: lesions that usually occur on the outer layer of the cornea. Red eye is one of the most common symptoms of this disease.

Red eye can also be associated with other serious diseases such as acute attack of glaucoma or endophthalmitis, which require urgent treatment. As it is a symptom that is common to multiple eye conditions (some of which have a higher associated risk), it is important to see an ophthalmologist when the first symptoms appear in order to ensure a rapid diagnosis and thus avoid possible complications.


As it is a disorder that appears in many eye conditions, the treatment of red eye will vary depending on the condition from which it derives.