The most common reasons, roughly in order of how often they show up in clinic.
Morning dry eye is rarely one single problem — it is usually a combination of what happens to your eyes overnight and the state your tear film was in when you went to bed. Working through the list below, from the most common to the less common, covers roughly 90% of cases.
About 1 in 5 adults (roughly 20%) sleep with their eyes partially open, often without knowing it. The gap can be just a millimetre or two, but over seven or eight hours the exposed cornea loses moisture steadily, producing gritty, burning eyes first thing in the morning. A partner may notice you sleep with a visible sliver of white, and some people wake with one eye drier than the other depending on sleeping position and pillow pressure.
The meibomian glands along the eyelid margins produce the oily layer that stops tears evaporating. When the ducts become blocked — from staring at screens, incomplete blinking, or simple age — the oil thickens and the tear film evaporates faster. MGD affects roughly 20–40% of adults and is the most common cause of evaporative dry eye overall. Morning symptoms are typical because the glands do their main work overnight, and a blocked gland simply cannot keep up.
Blink rate drops from a normal 15–20 times a minute to as few as 5–7 during intense screen use, and many screen blinks are partial, so the oil glands are never squeezed properly. Up to 70% of computer workers report eye strain symptoms. The effects compound overnight: you go to bed with an already-thin tear film, and the night finishes the job.
Bedroom fans, air conditioning, and heaters all accelerate tear evaporation, and low humidity in winter or in air-conditioned rooms makes it worse. Sleeping with the head near a draught or under a ceiling fan is a classic but easily missed cause. A simple humidity change often resolves morning dryness that no drop has fixed.
Antihistamines, decongestants, antidepressants, and blood-pressure medications all reduce tear production. CPAP users with a poorly fitted mask can have air leak into the eyes at night. Autoimmune conditions such as Sjögren's syndrome, rheumatoid arthritis, and thyroid disease also cause dry eyes, and they are worth considering if dryness is severe or comes with a dry mouth.
Blepharitis (inflammation of the eyelid edges, often with crusting at the lash line) and conditions that pull the eyelids away from the eye, such as age-related eyelid laxity or previous surgery, can leave a gap that never quite closes. Rosacea is also linked to both blepharitis and MGD.
Tear production declines with age, and roughly a third of people over 50 report dry eye symptoms. Women are about twice as likely to be affected, with changes around menopause a common trigger because oestrogen and androgen levels influence the tear and oil glands.
The right fix depends entirely on the mechanism. If your eyes are open at night, a sleep mask or eyelid tape helps; if the oil glands are blocked, warm compresses are the answer; if it is the bedroom air, a humidifier beats every drop on the shelf. Treating the wrong cause is why so many people end up with a drawer full of eye drops that never quite worked. For the practical routine, see the relief page.
Most of these causes are managed at home, but a few versions need professional input:
If any of these fit, use the Doctor page rather than continuing on your own.