Dry eye is a condition where your eyes don’t produce enough tears or the tears evaporate too quickly, leaving the surface of your eye inadequately protected. It’s one of the most common reasons people visit an eye doctor, and it ranges from mild irritation to a chronic condition that can damage your cornea over time. Understanding what’s actually happening with your tears, and why, makes it much easier to manage.
How Your Tear Film Works
Your tears aren’t just salt water. They form a three-layered film that coats the front of your eye every time you blink. The outermost layer is oily, which slows evaporation. The middle layer is watery and makes up most of the tear’s volume, delivering moisture and nutrients to the cornea. The innermost layer is mucus, which helps the watery layer spread evenly and stick to the eye’s surface.
When any one of these layers is disrupted, the tear film becomes unstable. It breaks apart between blinks, exposing the cornea to air. That exposed surface is what creates the gritty, burning, stinging sensation most people associate with dry eye. Paradoxically, dry eye can also cause excessive tearing, because the irritation triggers a flood of low-quality reflex tears that don’t actually protect the surface.
The Two Types of Dry Eye
Dry eye falls into two broad categories based on what’s going wrong with your tears.
Evaporative dry eye is the more common type. It happens when the oily outer layer of your tear film is insufficient, so tears evaporate faster than they should. The root cause is usually dysfunction in the meibomian glands, tiny oil-producing glands along the edges of your eyelids. When those glands become blocked or inflamed, they don’t release enough oil. Over time, the chronic inflammation can further damage the glands, creating a worsening cycle.
Aqueous deficient dry eye means your eyes simply aren’t producing enough of the watery component. This type is less common and can point to an underlying autoimmune disorder. Conditions like Sjögren’s syndrome can gradually destroy the lacrimal glands, the glands responsible for producing the watery layer. Many people have a combination of both types.
Common Causes and Triggers
Dry eye has a long list of contributing factors, and most people can point to more than one.
Screen time is a major modern trigger. When you stare at a phone, computer, or TV, your blink rate drops significantly. Research on adolescents found that people with high screen exposure blinked roughly 10.9 times per minute, compared to 15.4 times per minute in low-exposure groups. Fewer blinks means the tear film isn’t being refreshed as often, and more of those blinks are incomplete, leaving parts of the eye exposed.
Medications are another underappreciated cause. An estimated 62% of dry eye cases in older adults can be attributed to systemic medications. The list includes antihistamines, antidepressants, blood pressure medications, diuretics, anti-anxiety drugs, and common pain relievers like ibuprofen and aspirin. Some of these drugs reduce tear production directly, while others are secreted into the tears themselves, forming tiny crystals that irritate the eye surface. Even glaucoma eye drops, which are supposed to help your eyes, cause burning and dryness in up to 47% of patients.
Other common contributors include aging (tear production naturally declines over time), hormonal changes during menopause, contact lens wear, low-humidity environments, wind exposure, and air conditioning or forced-air heating.
What Dry Eye Feels Like
The symptoms aren’t always what you’d expect from the name. Yes, your eyes may feel dry. But they can also feel scratchy, like something is stuck in them, or burn and sting without an obvious cause. Redness, blurred vision that clears after blinking, and sensitivity to light are all common. Some people notice their eyes feel worst at the end of the day, while others wake up with discomfort because their eyes dried out overnight.
Many people dismiss these symptoms as just tiredness or allergies. The key difference is that dry eye symptoms tend to be persistent and worsen in specific environments: air-conditioned offices, airplanes, windy days, or after long stretches of reading or screen work.
How Dry Eye Is Diagnosed
Eye doctors use a few straightforward tests. The tear break-up time test involves placing a small amount of dye on your eye and watching through a microscope to see how quickly dry spots appear after you blink. If your tear film breaks apart in under 10 seconds, that’s considered abnormal.
Another common test measures how much moisture your eyes produce over five minutes using a small strip of paper placed along the lower eyelid. Wetting of more than 10 millimeters is normal, 6 to 10 millimeters is borderline, and 5 millimeters or less indicates severe aqueous deficiency. Neither test is painful, though the paper strip can feel slightly uncomfortable.
What Happens if Dry Eye Goes Untreated
Mild dry eye is uncomfortable but not dangerous. Chronic, untreated dry eye is a different story. Without an adequate tear film, the cornea loses its primary defense against infection and physical damage. Dry eye is a recognized risk factor for corneal ulcers, which are open wounds on the cornea that can cause permanent vision loss if not treated promptly. The progression typically starts with persistent inflammation, which can lead to tiny scratches or abrasions on the corneal surface. Those imperfections become vulnerable to infection, and infection can develop into an ulcer.
This doesn’t happen overnight, and most people with dry eye will never reach this stage. But it’s the reason chronic symptoms are worth addressing rather than simply tolerating.
Treatment Options
Treatment depends on severity and type, and most people start with the simplest interventions before moving to prescriptions.
Artificial tears (over-the-counter eye drops) are the first-line treatment for mild dry eye. Preservative-free formulations are gentler for frequent use. For evaporative dry eye specifically, warm compresses applied to the eyelids for 5 to 10 minutes can help soften blocked oil in the meibomian glands, followed by gentle lid massage to encourage the oil to flow.
When over-the-counter drops aren’t enough, prescription options target the underlying inflammation that drives chronic dry eye. Several prescription eye drops work by calming the immune response on the eye’s surface, allowing the tear glands to function more normally. The FDA approved a new dry eye drug, acoltremon (brand name Tryptyr), in May 2025, adding to the growing list of prescription options for people who haven’t responded to earlier treatments.
For severe cases, doctors may recommend procedures to plug the tear drainage ducts (tiny openings in the inner corners of your eyelids), which keeps whatever tears you do produce on the eye surface longer. In-office treatments that use heat or pulsed light to unclog meibomian glands have also become more widely available.
Practical Steps to Reduce Symptoms
Environmental adjustments make a real difference. Indoor humidity of about 45% or higher is best for your eyes, so a humidifier in your bedroom or office can help, especially during winter when heating systems dry the air. Positioning yourself so that air vents, fans, or heaters aren’t blowing directly at your face reduces evaporation from the eye surface.
If you spend long hours at a screen, the 20-20-20 rule is a practical habit: every 20 minutes, look at something 20 feet away for 20 seconds. This prompts natural blinking and gives your tear film a chance to recover. Consciously blinking more fully during screen work also helps, since incomplete blinks are part of what destabilizes the tear film during device use.
Wraparound sunglasses or moisture chamber glasses can protect your eyes from wind and dry air outdoors. Omega-3 fatty acids from fish or supplements have shown some benefit in improving tear quality, though results vary. Staying well hydrated won’t cure dry eye on its own, but dehydration makes any tear deficiency worse.