Glaucoma Eye Drops, Dry Eye, and Sleep Quality: Exploring Hidden Connections and What Patients Can Do

Introduction

People with glaucoma often rely on daily eye drops to protect their vision. These medications lower eye pressure, but over months or years they can sometimes irritate the ocular surface (the cornea and surrounding tissues). Many glaucoma drops contain preservatives or active ingredients that may dry out the eyes or cause inflammation. At the same time, dry eye disease (insufficient or poor-quality tear film) is common and can disrupt sleep. In fact, recent research shows that people with dry eye often report worse sleep quality than those without it (pmc.ncbi.nlm.nih.gov) (pubmed.ncbi.nlm.nih.gov). This article explores how glaucoma eye drops might contribute to dry eye and whether that could affect sleep – especially REM (rapid eye movement) sleep, when the eyes rock back and forth under closed lids. We’ll look at what studies say about these links and suggest practical steps patients can take.

How Glaucoma Eye Drops Affect the Ocular Surface

Glaucoma eye drops protect vision but can irritate the eye. This irritation usually comes from the medicine’s ingredients or the preservatives used to keep the drops sterile. For example, benzalkonium chloride (BAK) is a very common preservative in glaucoma medications, and it is known to damage the tear film and cells on the eye surface (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Even small doses of BAK can break apart the protective tear layer, causing burning, stinging, redness or a foreign-body sensation (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Newer formulations try to minimize this by using gentler preservatives (like SofZia or Polyquad (pmc.ncbi.nlm.nih.gov)) or going preservative-free. Clinical studies show that patients on preservative-containing eyedrops report much more irritation and surface damage than those using preservative-free versions (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov).

Besides preservatives, the active ingredients of glaucoma drugs can also affect tear production. For instance, beta-blocker drops (like timolol) can reduce tear secretion and cause dryness. Other drugs (carbonic anhydrase inhibitors, alpha agonists, and even some prostaglandin analogs) may also cause mild burning or redness in sensitive patients (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Over time, the chronic use of these medicines can inflame the ocular surface and even change the glands that keep the eyes lubricated. A Korean study noted that glaucoma medications – not just their preservatives – can cause chronic ocular surface inflammation and alter the tear-producing meibomian glands (pmc.ncbi.nlm.nih.gov).

Several studies have confirmed that glaucoma patients tend to show signs of dry eye. For example, Sahlu and colleagues found that people on multi-drop glaucoma therapy had significantly more dry eye findings (like shorter tear break-up time and more corneal staining) than control subjects (pmc.ncbi.nlm.nih.gov). The Pakistani study reported lower tear film stability (short TBUT) and higher corneal staining in glaucoma patients, especially those using multiple medications per day (pmc.ncbi.nlm.nih.gov). Importantly, more drops per day or more medications generally means worse ocular surface effects. In one trial, patients on glaucoma drugs had a significant drop in the lipid layer of their tears and worse dry-eye symptom scores in the first 6–12 months of treatment (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). In short, long-term use of glaucoma eye drops – especially in polypharmacy – can lead to or worsen dry eye disease (DED) (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov).

Dry Eye Symptoms and Sleep Quality

Dry eye disease means the eyes do not make enough quality tears or the tears evaporate too quickly. This leads to a chronic feeling of dryness, burning, stinging, grittiness or blurred vision (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). In fact, dryness, itchiness, light sensitivity, or pain are common symptoms noted in surveys (pmc.ncbi.nlm.nih.gov). These symptoms can be quite uncomfortable at night. For example, dry eyes may keep the cornea slightly irritated under the eyelids, and some people may not close one eye fully during sleep, making dryness worse. The inflammation of dry eye (more immune cells on the surface) can also make the eyes feel gritty or painful (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov).

It’s not surprising, then, that dry eye has been linked to poor sleep quality. A large meta-analysis (review of many studies) found people with dry eye had significantly worse sleep scores (Pittsburgh Sleep Quality Index) than healthy controls (pmc.ncbi.nlm.nih.gov). On average, dry eye patients reported longer time to fall asleep, more frequent nighttime awakenings, and more daytime sleepiness (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). One big population study (71,761 adults) found that 36% of dry eye sufferers had poor sleep versus 25% of controls (pubmed.ncbi.nlm.nih.gov). After adjusting for other health factors, dry eye still carried a 20% higher odds of poor sleep (pubmed.ncbi.nlm.nih.gov). Notably, people with very frequent dry eye symptoms were almost as likely to have bad sleep as people with sleep apnea or arthritis (pubmed.ncbi.nlm.nih.gov).

Several theories explain this link. Direct eye discomfort could certainly wake someone up. Inflammation and pain might make falling asleep harder (pmc.ncbi.nlm.nih.gov). Some people with dry eye also feel anxious or depressed about their symptoms, which in turn hurts sleep (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Specialized eyelid or tear deficiencies could even cause micro-awakenings. For instance, incomplete eyelid closure (lagophthalmos) can happen in dry eyes, letting air dry the cornea overnight. One review noted dry eye patients may keep blinking or moving their eyes in sleep to find relief (pmc.ncbi.nlm.nih.gov), thus fragmenting sleep.

Importantly, treating dry eye can improve sleep. A small study of 71 dry-eye clinic patients found that those newly treated with eye drops reported significant improvements in their sleep quality (PSQI) after treatment (pmc.ncbi.nlm.nih.gov). Patients with recent-onset dry eye had better sleep improvement than those with chronic dry eye (pmc.ncbi.nlm.nih.gov). In other words, relieving eye irritation goes hand-in-hand with sleeping better. This suggests that any steps improving tear film (like artificial tears or ointments) may help one sleep more soundly.

REM Sleep and Ocular Surface

During REM sleep, the eyes move rapidly under closed lids. Some scientists have proposed that these movements serve to refresh the tear film across the cornea (pubmed.ncbi.nlm.nih.gov). In this theory, each rapid eye movement spreads tears and humidifies the eye surface, preventing stagnation. If true, then a well-lubricated eye might use REM to stay moistened. But in dry eye, an already-irritated surface might not tolerate these motions as well. Unfortunately, no clinical studies have directly asked whether REM-induced movements cause discomfort in people with dry eyes or on glaucoma drops. The idea remains speculative. In practice, we do not know if REM eye motion disturbs someone’s sleep or eyes when their surface is compromised. A small animal study did show that depriving animals of REM sleep changed hormone levels needed for tear glands (pmc.ncbi.nlm.nih.gov), but human data are lacking. What is clear is that drag or friction is possible if the tear film is very thin. Until research catches up, the patient’s best approach is to keep the eyes as wet and comfortable as possible (see below).

Glaucoma Patients and Sleep – What Do Studies Show?

You might wonder if people with glaucoma have more sleep problems overall. The answer is mixed. Some surveys report that glaucoma patients complain of more disturbed sleep or insomnia. For example, a study in Ethiopia found 82% of glaucoma patients had poor sleep (using PSQI) compared to 56% of controls (pmc.ncbi.nlm.nih.gov). Poor sleep was linked there to older age, depression, and worse vision among the glaucoma group (pmc.ncbi.nlm.nih.gov). This suggests sleep issues in glaucoma might be due to factors like vision loss, mood, or overall health rather than drops alone.

On the other hand, an objective sleep study in France (using overnight polysomnography) found no significant differences in sleep stages or total sleep time between glaucoma patients and people without glaucoma (pmc.ncbi.nlm.nih.gov). After carefully adjusting for age, health and other factors, the researchers reported that the sleep architecture (including time in REM, deep sleep, etc.) was very similar (pmc.ncbi.nlm.nih.gov). In short, well-controlled studies have not consistently found global sleep disturbances in glaucoma per se.

It may be that any small effect from glaucoma medications on sleep is overshadowed by other issues (like older age or stress). Nevertheless, the overlap of glaucoma and dry eye is enough to warrant attention, since each alone can influence sleep (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Notably, damage to light-sensing retinal cells in glaucoma can alter circadian rhythms (pmc.ncbi.nlm.nih.gov), so doctors worry about that too. But current evidence does not clearly show, for example, that REM sleep is objectively reduced in glaucoma patients.

What Patients Can Do

If you have glaucoma and eye drops caused irritation or if you notice your eyes are dry at night, there are several steps to try:

Ask about preservative-free options. Today many glaucoma medications come in preservative-free bottles. Studies show that switching from preserved to preservative-free eye drops dramatically reduces symptoms of dry eye (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Even if no specific preservative-free version of your exact drop exists, your doctor may be able to switch you to an equivalent drug in a gentler formula. This simple step often helps ocular comfort.
Reduce the number of different drops if possible. Combination eye drops (e.g. one bottle that has two medicines mixed) can cut down on how many total bottles and toxins you use. Fewer drops per day generally means less cumulative exposure to preservatives (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov).
Use lubricating tears regularly. Over-the-counter artificial tears (preferably preservative-free) are the first-line relief for dry eye. Use them several times a day and especially before bedtime. A brief liberal drop 10–15 minutes after your glaucoma drop can both protect the medicine and soothe the eye. It’s best to use a stand-alone tear drop rather than an ointment right before driving (blurred vision risk), but an ointment at night can keep eyes moist under the eyelids.
Warm compresses and lid hygiene. If your doctor finds you have blocked oil glands (meibomian gland dysfunction), using a warm compress on closed lids for 5–10 minutes daily can melt and release oils that stabilize the tear film. Gently scrubbing your lashes with baby shampoo or a lid wipe can also help if there is debris. Healthy meibomian function means better tear quality and less surface evaporation.
Check medication timing. Sometimes switching the time of day you install drops can help. For example, many prostaglandin analogues (like latanoprost/travoprost) are given at bedtime, which can reduce daytime redness. Conversely, beta-blockers or alpha-agonists are often dosed in the morning. Discuss with your doctor whether giving a particular drop in the morning versus evening affects your comfort. Also, wait a few minutes between different drops so they do not wash each other out.
Optimize your environment. Use a humidifier in dry climates or heated rooms. Take breaks from screen time and blink often when on computers or phones. Wear wraparound glasses or goggles in windy or air-conditioned environments to prevent tear evaporation.
Check systemic factors. Stay hydrated and humidify your room at night. Good sleep hygiene (regular schedule, reduced caffeine, dark bedroom) is always helpful. If you have obstructive sleep apnea, use your CPAP correctly – but note that air leaks into the eyes can actually worsen dryness. If eye irritation from CPAP is a problem, talk to your sleep doctor about mask fit.
Consult for supplemental treatments. Some patients ask about omega-3 fatty acids or flaxseed oil to improve tear quality. Clinical trials (like the DREAM study) have had mixed results (pmc.ncbi.nlm.nih.gov), so these are optional. Some also try RAAS blockers or multitasking medications under research, but no standard vitamin/herb therapy is proven for dry eye yet.
Get mental health support if needed. Chronic eye problems and vision concerns can lead to anxiety or insomnia. As one sleep/psychiatry study suggests, treating mood or sleep disorders (for example with relaxation therapy or even a short course of a sleep aid) can help dry-eye patients sleep better (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov).

If you continue having sleep problems or eye pain despite all steps, talk to both your eye doctor and primary care provider. They might coordinate care (for example, managing a tear duct plug, prescribing anti-inflammatory eye drops, or referring to a sleep specialist).

Research Gaps and Future Directions

Our understanding of the glaucoma–dry eye–sleep connection is still evolving. Key gaps include:

REM-specific effects. We lack direct studies on whether rapid eye movements in REM cause discomfort in dry eyes, or whether healthy REM movements improve tear distribution. An intriguing 2007 hypothesis suggested REM lubricates the eye (pubmed.ncbi.nlm.nih.gov), but this is unproven. Animal studies hint at hormonal links between REM sleep and tear glands (pmc.ncbi.nlm.nih.gov), but human research is needed. Future studies using specialized eye-tracking during sleep could shed light on what happens to a dry eye during REM.
Objective sleep measures. Most existing data on glaucoma and sleep come from surveys (PSQI) or small sleep studies (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Larger polysomnography trials could test if stages like REM are actually altered by glaucoma drops. For instance, researchers could monitor tear film health and sleep simultaneously.
Long-term outcome trials. So far, we have evidence from cross-sectional and short-term studies. Longer trials could see if switching to preservative-free drops not only improves dry eye signs, but also improves sleep measures over months. Similarly, studying whether aggressive dry-eye therapy (lubricants, plugs, etc.) in glaucoma patients leads to objectively better sleep (actigraphy or questionnaires) would be valuable.
Personal factors. Which patients are at highest risk? The preservative-free review suggests the elderly, those with existing dry eye, heavy drop usage, or high screen time might especially benefit from preservative-free therapy (pmc.ncbi.nlm.nih.gov). More data on genetics, hormone levels, or nerve sensitivity could personalize these strategies.

In summary, there is a clear body of evidence that glaucoma medications can harm the ocular surface (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov), and that dry eye impairs sleep quality (pmc.ncbi.nlm.nih.gov) (pubmed.ncbi.nlm.nih.gov). Though direct links between glaucoma drops and sleep remain under-studied, patients worried about nighttime eye comfort have options. Using gentler drops, adding lubricants, and addressing dry eye proactively can make a difference. Clinicians and researchers should continue to explore these links, as improving eye comfort might well improve sleep and quality of life for people on long-term glaucoma therapy.

Conclusion

Glaucoma eye drops save vision but can take a toll on the eye’s surface over time. Preservatives like BAK and multi-drop regimens often lead to dry eye symptoms (burning, stinging, tear film instability) (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Persistent dry eye in itself is linked to worse sleep, longer time to fall asleep and more awakenings (pmc.ncbi.nlm.nih.gov) (pubmed.ncbi.nlm.nih.gov). Because of this, glaucoma patients should be aware of potential sleep impacts. The good news is many practical steps can help: switching to preservative-free or fewer drops, using artificial tears especially at bedtime, maintaining eyelid health, and following good sleep habits. Treating dry eye not only comforts the eyes, but studies show it also tends to improve sleep (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Though more research is needed (for instance, on how REM eye movements affect dry eyes), the best current advice is to preserve the ocular surface as much as possible. With the right strategies, patients can often reduce eye discomfort and protect both their vision and their sleep quality.