Dry eye syndrome is a common cause of eye irritation. It mainly affects older people. Dry eye syndrome (also known as keratoconjunctivitis sicca, or simply dry eyes) occurs when there is a problem with the tear film that normally keeps the eye moist and lubricated. It can occur as a result of various conditions. The causes include:
•Ageing. You tend to make fewer tears as you get older. In particular, some women notice dry eyes developing after the menopause.
•Medication. Some medicines sometimes have a side-effect of causing dry eyes, or make dry eyes worse. These include: diuretics (water tablets); some antidepressants; antihistamines; some treatments for anxiety and other psychological problems; the contraceptive pill; some eye drops used to treat other eye conditions.
•Illness. Some people develop dry eyes as a symptom of a more general disease. For example, dry eyes may occur with rheumatoid arthritis, systemic lupus erythematosus (SLE), and Sjögren's syndrome. In these situations you would normally have other symptoms in other parts of the body. For example, joint pains.
•Increased evaporation of tears. This may be due to:
- Low humidity. For example, from central heating or air conditioning.
- Low blink rate, often combined with opening your eyes wider than normal. For example, spending a long time looking at a computer, TV or microscope.
- Windy conditions when you are outside.
- Inability to cover the eyes completely when closing the eyelids.
What are the symptoms of dry eyes?
- Irritation in the eyes. The eyes may feel gritty or burning. However, the eyes do not go red. If they do, another eye problem or a complication is usually present.
- Slight blurring of vision from time to time. However, dry eyes do not affect the seeing part of the eye, and dry eyes do not usually cause permanent damage to vision.
- You may not like bright lights.
- If you wear contact lenses, you may find they become uncomfortable.