Dry Eye Disease
What is Dry Eye Disease?
Dry eye disease (DED) is a chronic condition in which the eyes do not produce enough tears, or the tears produced are of poor quality and evaporate too quickly. This leads to inflammation of the ocular surface and a range of uncomfortable symptoms.
Dry eye is one of the most common conditions seen in eye clinics and affects an estimated 1 in 3 people at some point in their lives. It is more common in women, older adults, contact lens wearers, and screen users.
The Tear Film
A healthy tear film has three layers:
- Outer oil layer (produced by meibomian glands in the eyelids): prevents evaporation
- Middle water layer (produced by lacrimal glands): provides moisture and nutrients
- Inner mucin layer (produced by conjunctival cells): helps tears spread evenly
Dysfunction in any layer causes dry eye. The most common cause is meibomian gland dysfunction (MGD) — blocked oil glands leading to rapid tear evaporation.
Symptoms
- Grittiness, burning, or stinging — often worse later in the day
- Paradoxical watering (reflex tearing from irritation)
- Blurred vision that temporarily clears with blinking
- Sensitivity to light, wind, smoke, or air conditioning
- Discomfort with contact lens wear
- Redness
- Symptoms often worse in air-conditioned or heated environments and when using screens
Common Causes
- Meibomian gland dysfunction (MGD) and blepharitis
- Age-related decline in tear production
- Screen use (reduced blink rate)
- Contact lens wear
- Medications (antihistamines, antidepressants, beta-blockers, HRT)
- Autoimmune conditions (Sjogren's syndrome, rheumatoid arthritis, lupus)
- Post-surgical (after cataract surgery, LASIK, corneal procedures)
- Environmental factors (low humidity, air conditioning, heating)
When to Seek Help
- If symptoms are significantly affecting your quality of life or daily activities
- If over-the-counter lubricants are not providing adequate relief
- If you have associated redness, photophobia, or vision changes
Treatment
Treatment is stepped according to severity, from preservative-free lubricating drops through to anti-inflammatory medications, punctal plugs, and specialist procedures. Identifying and treating the underlying cause (particularly MGD and blepharitis) is the foundation of effective management.