Persistent dry eyes are one of the most common eye complaints, affecting anywhere from 5% to 50% of people depending on age, environment, and health factors. The feeling typically comes down to one problem: your tear film isn’t doing its job. Either you’re not producing enough tears, or the tears you do produce are evaporating too quickly. Understanding which category you fall into is the key to actually fixing it.
How Your Tear Film Works (and Fails)
Your tears aren’t just saltwater. They have three distinct layers: a thin mucus layer that helps tears stick to the eye’s surface, a watery middle layer that provides moisture and nutrients, and a top oil layer that prevents everything underneath from evaporating. That oil layer comes from tiny glands along the edges of your eyelids called meibomian glands, and problems with these glands are the single most common cause of chronic dry eyes.
When these glands get clogged or start producing thicker, lower-quality oil, the protective barrier breaks down. Without it, your tears evaporate off the surface of your eye far faster than they should. This is called evaporative dry eye, and it accounts for the majority of cases. The other type, where your tear glands simply don’t produce enough liquid, is less common but can be more difficult to treat.
Screen Time Is a Major Culprit
You normally blink about 17 times per minute. When you’re staring at a screen, that drops to roughly 4 times per minute. Each blink spreads a fresh layer of tears across the surface of your eye and stimulates oil release from those lid glands. Cut your blink rate by more than 75%, and your tear film dries out between blinks faster than it can be replenished.
This is why your eyes often feel worse by the end of a workday or after a long stretch of scrolling. The fix sounds simple: blink more. In practice, it helps to follow the 20-20-20 rule. Every 20 minutes, look at something 20 feet away for 20 seconds. This naturally resets your blink rate and gives your tear film a chance to recover. Positioning your screen slightly below eye level also helps, because looking downward means less of your eye surface is exposed to the air.
Your Medication Could Be Drying You Out
Several widely prescribed medications reduce tear production as a side effect. Antidepressants are among the most common offenders. Tricyclic antidepressants decrease tear secretion by blocking the nerve signals that tell your tear glands to produce moisture. SSRIs and SNRIs can alter tear film production through their effects on the autonomic nervous system, which controls unconscious body functions like tear secretion. Even some newer antidepressants like mirtazapine list dry eye as a known side effect.
Antihistamines, whether taken for allergies or sleep, work by blocking the same chemical messenger (acetylcholine) that your tear glands rely on. Blood pressure medications, decongestants, and hormonal treatments like birth control pills can also contribute. If your dry eyes started or worsened around the time you began a new medication, that’s worth mentioning to your prescriber. Adjusting the dose or switching to an alternative can sometimes make a significant difference.
Low Humidity and Airflow
The air around you matters more than most people realize. Heated indoor air in winter, air conditioning in summer, ceiling fans, and airplane cabins all create low-humidity environments that pull moisture from your eyes. Keeping indoor humidity at 45% or higher is the general recommendation for eye comfort. A simple hygrometer (most cost under $15) can tell you where your home or office stands, and a humidifier can close the gap.
Direct airflow is especially problematic. If an air vent, fan, or car heater blows toward your face, your tears evaporate faster regardless of humidity levels. Redirecting vents or wearing wrap-around glasses outdoors on windy days are small changes that can have an outsized effect.
Autoimmune Conditions and Hormonal Shifts
When dry eyes are severe and accompanied by a persistently dry mouth, an autoimmune condition called Sjögren’s syndrome may be involved. In Sjögren’s, the immune system attacks the glands that produce tears and saliva. Diagnosis typically involves blood tests looking for specific antibodies, a tear production test where a small strip of paper is placed under the lower eyelid to measure moisture output over five minutes, and sometimes a biopsy of tissue from the inner lip.
Hormonal changes also play a role, particularly for women. Drops in estrogen during menopause, pregnancy, or while using certain birth control methods can reduce tear production and change tear composition. This is one reason dry eye prevalence is roughly twice as high in women as in men.
Choosing the Right Eye Drops
Over-the-counter artificial tears are the first line of relief for most people, but not all drops are created equal. Many contain a preservative called benzalkonium chloride (BAK), which keeps the bottle sterile but can damage the surface cells of your eye with repeated use. It disrupts the corneal barrier, kills goblet cells that produce tear-stabilizing mucus, and can trigger inflammation. The risk increases with frequency of use, so if you’re reaching for drops more than a few times a day, preservative-free single-use vials are the better choice.
If you already have irritated or damaged eye surfaces, even short-term use of preserved drops can make things worse. A good rule of thumb: occasional use of preserved drops is fine for most people, but anyone using drops daily as a routine should switch to preservative-free options. Your eye doctor can check for surface damage using special dyes that highlight areas of irritation under a microscope.
Omega-3s and Tear Quality
There’s reasonable evidence that omega-3 fatty acids can improve tear film stability, particularly the oil layer. The dose used in many clinical studies was 360 milligrams of EPA and 240 milligrams of DHA per day, split into two doses. That’s roughly equivalent to eating oily fish (salmon, sardines, mackerel) two to three times per week, or taking a standard fish oil supplement.
The effect isn’t immediate. Most studies measured improvements after several weeks to a few months of consistent intake. Omega-3s appear to work by reducing inflammation in the meibomian glands and improving the quality of the oil they secrete. They won’t replace drops for someone with significant dryness, but they can be a useful addition.
What an Eye Exam Looks For
If home remedies and over-the-counter drops aren’t cutting it, an eye care provider can run specific tests to figure out what’s going wrong. The Schirmer test places a small paper strip on your lower eyelid and measures how many millimeters of moisture it absorbs in five minutes. Less than 10 millimeters suggests your eyes aren’t producing enough tears.
Another key measurement is tear break-up time: how many seconds your tear film stays intact on the surface of your eye after a blink. Normal is 8 to 10 seconds or more. People with moderate dry eye from low tear volume often see their tear film break apart in just 2 to 3 seconds. These tests help determine whether your issue is insufficient tear production, excessive evaporation, or both, which directly shapes treatment.
Practical Habits That Add Up
Beyond drops and supplements, a few daily habits can meaningfully reduce chronic dryness:
- Warm compresses. A warm, damp cloth held over closed eyes for 5 to 10 minutes softens clogged oil in the meibomian glands. Doing this daily, especially before bed, helps restore the oil layer of your tear film over time.
- Lid hygiene. Gently cleaning along the lash line with diluted baby shampoo or pre-made lid wipes removes debris and bacteria that contribute to gland blockage.
- Hydration. Dehydration reduces tear volume. It’s not a cure, but consistently drinking enough water supports baseline tear production.
- Sleep quality. Your eyes recover overnight. Incomplete eyelid closure during sleep (more common than most people think) can cause dryness that’s worst in the morning. If you wake up with gritty, irritated eyes, this is worth investigating.
Dry eyes rarely have a single cause. For most people, it’s a combination of screen habits, environment, age, and sometimes medication or underlying health conditions stacking on top of each other. The good news is that each contributing factor you address chips away at the problem, and most people can get significant relief without anything more invasive than lifestyle changes and the right drops.