When face mask wearing became widespread during the COVID-19 pandemic, eye care practitioners began noticing a pattern that had not been clinically described before. Patients were presenting with new or significantly worsened dry eye symptoms that they could not explain – they had not changed their screen habits, their medications, their diet, or their environment in any obvious way. The one thing that had changed was that they were wearing a face mask for eight or more hours a day. The condition that emerged from this observation eventually received a clinical name: mask-associated dry eye, abbreviated MADE.
Several years on, masks are less universally worn than at the height of the pandemic, but they remain a daily reality for significant portions of the population – healthcare workers, individuals with immunocompromising conditions, people who wear masks on public transit, and those in industries where mask policies remain in effect. The clinical literature on MADE has continued to accumulate since the original case series and observational studies, and what has emerged is a coherent mechanistic picture of how mask wearing produces its effects on the ocular surface – and what can be done about it.
Contents
The Mechanism: Exhaled Air and the Ocular Surface
The central mechanism of MADE is physically straightforward. Most face masks – particularly surgical masks and cloth masks – do not form an airtight seal at the upper edge, which rests against the nose and cheek bridge. Exhaled air, which is warm, moist, and directed upward through the gap at the mask’s upper edge, creates a localized microclimate over the inferior cornea and lower conjunctiva. This upward airflow has several effects on the ocular surface that individually are modest but cumulatively produce significant tear film disruption.
First, the warm exhaled air elevates the temperature of the tear film in the inferior ocular surface region, increasing the evaporation rate from the tear film directly – warmer temperatures drive faster water vapor transfer. Second, the directional airflow component of the exhaled air creates the same accelerated evaporation effect that direct fan or vent airflow produces, continuously replacing the humid air layer adjacent to the tear film with the drier ambient air from slightly further away. Third, and perhaps most significantly, the exhaled air directed upward over the eye reduces the effective relative humidity in the immediate environment over the inferior cornea by creating a micro-turbulence pattern that disrupts the still humid boundary layer that would otherwise provide some protection against tear evaporation.
The inferior cornea and lower bulbar conjunctiva, which bear the brunt of this upward airflow exposure, show the most pronounced effects in clinical measurements. Tear film break-up time, measured by fluorescein staining and slit-lamp examination, is consistently shorter in the inferior cornea in mask wearers compared to controls and compared to the superior cornea in the same individuals – a topographic pattern that directly implicates the upward exhaled airflow as the mechanism rather than systemic effects of mask wearing.
What the Research Found
The clinical research on MADE developed rapidly during the pandemic period and produced a body of consistent findings across multiple countries and clinical settings.
A 2020 study published in the British Journal of Ophthalmology by Moshirfar and colleagues was among the first to formally characterize MADE, proposing the upward airflow mechanism and documenting the pattern in clinical observations. Multiple subsequent controlled studies measured objective ocular surface parameters in masked versus unmasked subjects and in the same subjects before and after masking.
Tear film break-up time was consistently reduced in masked versus unmasked conditions across studies, with the most pronounced reductions appearing after 30 to 60 minutes of continuous mask wear – consistent with the progressive disruption of the inferior tear film by sustained upward airflow exposure. A 2021 study by Boccardo measured tear film osmolarity, total tear meniscus height, and conjunctival goblet cell density in healthcare workers wearing surgical masks for six or more hours daily compared to controls, finding significantly elevated tear osmolarity, reduced meniscus height, and reduced goblet cell density in the masked group – objective signs of established dry eye disease rather than merely symptomatic perception.
Symptom surveys conducted during the pandemic period consistently found elevated dry eye symptom prevalence among mask wearers compared to pre-pandemic baselines and non-mask-wearing controls, with the elevation proportional to daily mask-wearing duration. Healthcare workers, who wore masks for the longest daily durations, showed the highest symptom prevalence rates.
Notably, N95 respirators, which form a much tighter seal against the face than surgical or cloth masks, showed smaller MADE effects in comparative studies – consistent with the mechanism, since a better seal at the upper edge reduces the upward airflow that drives tear film disruption. Surgical masks with a metal nose bridge strip that could be molded to the nose contour also showed smaller effects than loosely fitting masks, for the same reason.
Who Is Most Affected
MADE does not affect all mask wearers equally. Several pre-existing conditions and contextual factors determine how much ocular surface disruption a given mask-wearing exposure produces.
People with pre-existing dry eye disease – particularly the evaporative form driven by meibomian gland dysfunction – have less tear film stability reserve to absorb the additional evaporative stress of mask wearing. Their already-compromised lipid layer provides insufficient protection against the accelerated evaporation from upward airflow, and they reach symptomatic thresholds of tear film disruption faster and at lower levels of exposure than healthy eyes.
Contact lens wearers experience amplified MADE effects. Contact lenses increase tear evaporation rate above the baseline of uncorrected or spectacle-corrected eyes, because the lens surface itself evaporates differently from the underlying tear film. The combination of contact lens wear and mask-associated upward airflow creates a compounded evaporative stress that is more severe than either factor alone. Several studies documented a particularly high MADE symptom prevalence among contact lens wearers who masked throughout the workday.
Screen workers who wore masks while working at computers experienced compounded effects from MADE and screen-related blink rate reduction simultaneously. The already-reduced blink rate of screen work – dropping from a resting rate of approximately 15 blinks per minute to 3 to 5 during concentrated screen use – reduced the tear film replenishment frequency at precisely the time when mask-associated evaporation was accelerating tear film disruption. This combination produced symptom onset earlier in the workday and at higher severity than either stressor alone would predict.
Age is an independent risk modifier. The declining meibomian gland function and tear production of the perimenopause period and beyond reduces the buffering capacity that allows healthy younger eyes to tolerate evaporative stressors without reaching symptomatic thresholds. Older mask wearers were consistently more symptomatic in survey data than younger ones, holding mask-wearing duration constant.
The Ocular Surface Inflammatory Cascade
MADE is not simply a mechanical tear film disruption problem. In people who wear masks for prolonged daily periods over weeks and months, the sustained tear hyperosmolarity produced by accelerated evaporation triggers the inflammatory cascade that perpetuates dry eye disease independently of its original cause.
Tear hyperosmolarity activates mitogen-activated protein kinases in corneal and conjunctival epithelial cells, triggering release of pro-inflammatory cytokines including IL-1β, TNF-α, and MMP-9. These cytokines damage goblet cells – which produce the mucin layer critical for tear film adhesion – and impair the function of the conjunctival epithelium that produces and regulates tear film components. Once goblet cell density is reduced and conjunctival inflammation is established, the dry eye cycle persists even if the original triggering stressor – the mask – is removed or reduced.
This explains why some people who developed MADE during periods of heavy mask wearing found that their symptoms did not fully resolve when mask wearing decreased. The inflammatory cycle, once initiated, required active management rather than simply removal of the triggering exposure. For these individuals, treatment appropriate to established dry eye disease – rather than simple exposure reduction – was necessary.
Practical Management Approaches
Several strategies reduce MADE symptoms with varying degrees of evidence and practicality, and combining approaches addresses different aspects of the mechanism.
Improving mask fit at the upper edge is the most direct mechanical intervention, targeting the upward airflow at its source. Moldable metal nose strips that conform closely to the nasal bridge reduce the gap through which exhaled air escapes. Medical-grade tape applied along the upper mask edge – as used by surgical staff before ergonomic mask designs became available – provides a more complete seal. Masks with better upper-edge construction, including some designs with pre-formed nose bridges, show smaller MADE effects in comparative assessments.
Lubricating eye drops used proactively during mask-wearing periods – not just reactively after symptoms are established – maintain tear film integrity during the increased evaporative stress. Lipid-containing drops that supplement the meibomian lipid layer provide more sustained protection than aqueous-only formulations, addressing the specific mechanism of accelerated evaporation. Preservative-free formulations are preferable for repeated daytime use during extended mask-wearing periods.
Environmental humidity management in the space where masks are worn reduces the ambient vapor pressure gradient that mask-associated airflow exploits. The same humidification strategies that benefit dry eye generally – targeting 40 to 50 percent relative humidity – are particularly valuable for mask wearers in dry indoor environments.
For contact lens wearers who must wear masks for extended periods, switching to daily disposable lenses eliminates the protein and lipid deposition that accumulates on reusable lenses and amplifies evaporative effects. Silicone hydrogel lenses with the highest available oxygen transmissibility maintain tear film quality better under the combined stress of lens wear and mask-associated evaporation than lower-Dk materials.
Meibomian gland health maintenance becomes particularly important for any patient who wears masks regularly. Warm compress therapy, lid hygiene, and omega-3 fatty acid supplementation for meibomian lipid quality support the lipid layer that is the primary protection against the evaporative stress masks introduce. The full dry eye management picture including meibomian gland considerations is covered in the article on dry eyes as you age.
Note: Mask-associated dry eye symptoms that persist, worsen, or do not respond to the management strategies described here warrant evaluation by an eye care professional. Prolonged dry eye inflammation, even when initially triggered by an environmental stressor, can establish an independent inflammatory cycle requiring prescription anti-inflammatory treatment. This is particularly relevant for contact lens wearers or those with pre-existing dry eye who experience significant symptom escalation during extended mask-wearing periods.
A Condition That Outlasted Its Original Context
MADE emerged from an unprecedented public health situation, was described and characterized in the clinical literature with unusual speed, and produced research contributions that have deepened the understanding of how environmental airflow affects tear film stability in ways that extend well beyond mask-specific contexts. The mechanism identified in mask wearers – upward airflow from below disrupting the inferior tear film – illuminates why any source of low-level upward airflow over the face, including car heating vents directed at the lower face, can produce similar patterns of inferior corneal dry eye.
For those experiencing dry eye in contexts of regular mask wear, the article on how indoor air quality affects tear film stability covers the complementary environmental variables that operate alongside mask-associated airflow effects. Nutritional support for tear film quality through omega-3 fatty acids and the ocular surface-supporting nutrients covered in the Performance Lab Vision review provides a foundation that environmental management builds on rather than replaces.
