What is dry eye disease?
Your tears form a thin film that keeps the surface of the eye smooth, clear, and comfortable. Dry eye disease means this is no longer working well. It is one of the most common reasons people visit an eye doctor, and it is a real disease, not just a nuisance.
Cross-section of the tear film covering the cornea: mucin (violet), aqueous (blue) and lipid (amber) layers. Drag to rotate — and see how the film breaks down when a single layer fails.
What does it feel like?
- Burning, stinging, or a gritty "sand in the eye" feeling
- Redness and tired eyes, especially at the end of the day
- Blurred vision that clears when you blink
- Watery eyes (irritation can trigger reflex tearing)
- Discomfort in wind, air conditioning, or after long screen use
Why does it happen?
There are two main mechanisms, and many people have a mix of both:
- Evaporative dry eye: tears dry up too fast. The most common cause is (MGD), where the tiny oil glands in the eyelids become blocked. Without a good oil layer, the tear film evaporates like water on a hot pan.
- Aqueous-deficient dry eye: the tear glands do not make enough of the watery part of tears. This can come with age, some medicines, or general health conditions such as .
Plump oil sacs (acini) surround an open central duct, and oil flows freely out of the orifice into your tear film.
Meibomian glands inside the eyelid make the oil that keeps your tears from evaporating. Drag to rotate — and see how the gland changes as blockage progresses.
Long screen hours (we blink less and blink incompletely), contact lenses, some common medicines, and dry or windy air all add to the problem.
How do we examine it?
A dry eye workup is painless and usually includes:
- A short questionnaire about your symptoms
- : how many seconds your tear film stays stable after a blink
- : safe colored drops (fluorescein and lissamine green) that show dry or damaged spots on the eye surface
- : infrared imaging that shows the oil glands inside your eyelids
- Sometimes a tear salt level (osmolarity) or a tear-volume test
These tests tell us not only whether you have dry eye, but which type you have, and that guides treatment.
Simulated tear film after a few blinks: Stable
Watch how each blink repaints the tear film — and what happens when it evaporates too quickly.
How is it treated?
Treatment climbs a ladder, matched to your type and severity:
- Daily habits: screen breaks, full blinks, a humidifier, and avoiding direct fans or air conditioning
- Artificial tears: preferably preservative-free; lipid-containing drops help when oil is the problem
- Eyelid care: warm compresses and gentle lid cleaning to unblock the oil glands
- Prescription drops: anti-inflammatory medicines such as or when inflammation drives the disease
- In-office procedures: heat-and-expression treatments for the oil glands, or for lid rosacea and MGD
- For severe disease: that keep tears in the eye longer, drops prepared from your own blood serum, or special protective contact lenses
Dry eye is usually a chronic condition, but with the right combination of measures, most patients reach real and lasting comfort.
Key points
- Dry eye is a real and very common disease — you do not have to simply live with it.
- The most frequent cause is blocked oil glands in the eyelids, which makes tears evaporate too fast.
- A painless workup — a questionnaire, tear film tests, and gland imaging — shows which type you have.
- Treatment is a step-by-step ladder, from daily habits and drops to in-office procedures.
- With the right combination, most patients reach real and lasting comfort.
Whether this applies to you can only be decided after an examination.