In short
Dry eye happens when tears are insufficient or evaporate too quickly, and — somewhat counterintuitively — it can make eyes water as often as it makes them feel gritty and dry.
On this page
01
Two Different Ways Dry Eye Happens
Tears aren't just water — they're a thin film with a watery layer and an oily layer that keeps the watery layer from evaporating too fast. Dry eye happens either because too few tears are produced (aqueous-deficient) or, more commonly, because the oily layer is compromised and tears evaporate too quickly even when production is normal (evaporative, usually from meibomian gland dysfunction — clogged oil glands along the eyelid edge).
Aging, screen use with reduced blinking, contact lens wear, certain medications (antihistamines, some blood pressure medications, antidepressants), autoimmune conditions like Sjögren's syndrome, and prior LASIK surgery are all linked to dry eye through one or both of these mechanisms.
02
Symptoms — Including the Confusing Ones
Gritty, burning, or foreign-body sensations, redness, and light sensitivity are typical, often worse by the end of the day or after screen use, reading, or time in wind or air conditioning. Vision can blur intermittently and clear with blinking.
Watery eyes seem like the opposite of dry eye, but an unstable tear film can trigger reflex tearing — the eye overproducing watery tears to compensate for a poor-quality tear film, without fixing the underlying oil-layer problem. This is a common source of confusion for people who don't expect a 'dry eye' diagnosis when their main complaint is watering.
03
How It's Diagnosed
An eye doctor can often spot dry eye on exam, checking the tear film, the eyelid margins, and the cornea's surface with a special dye. A tear breakup time test measures how quickly the tear film destabilizes after a blink, and a Schirmer test measures tear production directly when aqueous deficiency is suspected.
Because dry eye symptoms overlap with allergies, infections, and other eye surface conditions, an exam is useful even for symptoms someone assumes are 'just dry eye' — particularly if over-the-counter drops haven't helped.
04
Treatment
Preservative-free artificial tears are the first step for mild dry eye, and warm compresses with gentle eyelid massage help when clogged oil glands are the main driver. Taking regular breaks from screens and using a humidifier in dry indoor air both help reduce evaporation.
For moderate to severe dry eye that doesn't respond to these measures, prescription anti-inflammatory eye drops, punctal plugs (small inserts that reduce tear drainage), and specific in-office treatments for gland dysfunction are all options an eye doctor can tailor to which mechanism is driving the problem.
05
When to See an Eye Doctor
Persistent symptoms despite regular over-the-counter drops, or dry eye alongside joint pain, dry mouth, or other autoimmune symptoms (which can point to Sjögren's syndrome), are worth a proper evaluation rather than continuing to self-treat indefinitely.
Eye pain (rather than the milder grittiness typical of dry eye), significant light sensitivity, or any change in vision should be seen promptly, since these can signal a different problem — such as a corneal abrasion or infection — that needs care beyond dry eye treatment. This matters especially for contact lens wearers: a red, painful eye in someone wearing contacts needs same-day care, since contact lens wear raises the risk of a corneal infection that can progress quickly.
Sources
- Dry Eyemedlineplus.gov
Share this story
Curious where your own values stand?
Two minutes from upload to a full visual picture. Free to analyze.