Dry eye disease

What it is

The tear film has three layers: mucin on the surface, watery tears in the middle, and an oily layer on top that slows evaporation. Dry eye is usually evaporative (MGD/blepharitis) or aqueous-deficient (Sjögren's, age, medications), and many people have a mix.

Symptoms

Paradoxically, dry eye often makes eyes water.

• Gritty, burning or sandy feeling
• Intermittent blur that clears with blinking
• Redness and tired eyes, worse with screens
• Watery eyes in wind or cold
• Difficulty wearing contact lenses
• Symptoms worse later in the day

Common causes

Ageing, screen use with reduced blink rate, contact lenses, air conditioning, autoimmune disease (including Sjögren's), diabetes, rosacea, previous laser eye surgery, and medicines such as antihistamines, antidepressants and isotretinoin. Post-menopausal hormone changes contribute in many women.

Treatment ladder

Start simple and step up if needed.

• Regular preservative-free lubricating drops
• Warm compresses and lid massage for MGD/blepharitis
• Omega-3 diet or supplements if advised
• Humidifier and screen breaks with full blinks
• Prescription anti-inflammatory drops (e.g. ciclosporin, lifitegrast) for persistent disease
• Punctal plugs, serum tears or specialist procedures in selected cases

Living with dry eye

It is usually long-term but flares can be controlled. Keep drops in a routine, protect eyes in wind, and review contact-lens type with your practitioner. Severe pain, a single very red eye or sudden vision change is not typical — seek assessment.

When to seek care

Book an eye test if symptoms persist despite 4–6 weeks of regular lubricants and lid care, if vision is affected, or if you need contact lenses for work. Urgent care for severe pain, light sensitivity or sudden vision loss.