Tears are important for our eyes as they help to protect, lubricate and clean them. When tears do not function properly they can cause dry eyes or, strange as it seems, watery eyes.
Dry eye disease is a common cause of irritated, red, and uncomfortable eyes. It can affect vision, the ability to read efficiently, and mood. It affects 20% of New Zealanders. The classic symptom of dry eye is a ‘gritty’, ‘burning’ sensation. Dry eyes may occur if you don’t produce enough tears or if you produce poor-quality tears. What is confusing is that sometimes a person with dry eye will actually experience a watery eye. This happens when, as a result of the dry surface, the eye sends a distress signal through the nervous system for more lubrication. In response, the eye produces extra tears, but these tears are too watery and don’t have the lubricating qualities or rich composition of normal tears.
Tears are a combination of water for moisture, oils that lubricate and control tear film evaporation, mucus for even spreading, and antibodies and special proteins for resistance to infection. These components are secreted by special glands around the eye e.g. small glands on the edge of the eyelid (Meibomian glands) secrete the oily film and might become blocked.
Aging is the most common cause of dry eye because as we get older tear production decreases. Hormonal changes such as those that occur in pregnancy, menstruation, and menopause can decrease tear production and quality. Some diseases and medications can cause symptoms of dryness too. Wind and hot dry climates, as well as poor air quality from pollution and cigarette smoke, can contribute to dry eyes. Heaters, air conditioning, and aeroplane travel may increase the evaporation of tears from the surface of the eye.
Insufficient blinking will make your eyes dry. This often occurs when staring at a computer screen for long hours.
Quite a few people experience dry eye contact lens wear because the lens materials tend to absorb tears away from the eye. There are a number of ways people describe dry eye symptoms with contact lenses:
Lens awareness - can feel the contact lens moving around, especially towards the end of the day.
Variable vision - especially towards the end of the day.
Gritty, scratchy-feeling eyes. Lenses feel dry.
Can’t wait to get the contact lenses out in the evening.
Complications from dry eyes include:
Eye infections: Tears protect the surface of the eye. Without adequate tears, there is an increased risk of eye infection.
Damage to the surface of the eye: If left untreated, severe dry eyes may lead to eye inflammation, abrasion of the corneal surface, corneal ulcer, and vision problems.
Decreased quality of life: Dry eyes can make it difficult to perform everyday activities, such as reading.
If you are experiencing dry eye symptoms, an eye examination will determine the underlying cause of the problem and set a management plan. Treatments can include lifestyle changes, lid hygiene regimes, and eyedrops.
Dry Eye Disease is often a chronic progressive condition, that if managed early results in better outcomes.