Dry Eyes

Dry eye disease has two overlapping drivers. In evaporative dry eye — by far the most common — the meibomian glands along the lid margin produce poor-quality oil, so the tear film breaks up within seconds and the surface dries between blinks. In aqueous-deficient dry eye the lacrimal glands simply make too little tear volume, which is what happens in Sjogren's syndrome. Most people have a mix of both. Screen work makes either version worse because blink rate drops sharply during concentrated visual tasks, and incomplete blinks fail to spread oil across the surface. Symptoms are often paradoxical: watery, reflex-tearing eyes are a classic dry eye presentation, because a dry surface triggers a flood of low-quality tears. Burning, grittiness, fluctuating vision that clears on blinking, and end-of-day fatigue are the usual complaints. Treatment that works targets the lid margin: sustained warm compresses to soften meibum, lid massage and cleaning, and preservative-free artificial tears used on a schedule rather than only when symptomatic. Preserved drops used more than four times daily can worsen surface inflammation. Omega-3 supplements were once standard advice, but the large DREAM trial found no benefit over olive oil placebo, which reset expectations considerably.

• •Burning or stinging
• •Gritty, foreign-body sensation
• •Fluctuating vision that clears when blinking
• •Reflex watering
• •Red, tired eyes worse late in the day
• •Contact lens intolerance

• •Meibomian gland dysfunction
• •Prolonged screen use
• •Ageing and menopause
• •Sjogren's syndrome and other autoimmune disease
• •Antihistamines, isotretinoin, antidepressants, diuretics
• •Dry, windy or air-conditioned environments

Meibomian gland dysfunction, reduced blink rate during screen use, ageing and post-menopausal hormonal change, autoimmune disease such as Sjogren's, medications including antihistamines, isotretinoin and antidepressants, contact lens wear, and low-humidity or air-conditioned environments.