Understanding Dry Eye Disease: The TFOS DEWS II Definition

Understanding Dry Eye Disease: The TFOS DEWS II Definition

The rise in dry eye disease (DED) has become impossible to ignore, and it has prompted the eye care community, including both optometrists and ophthalmologists, to come together and develop a more standardized way of defining and measuring the condition. In 2017, the TFOS DEWS II (Tear Film & Ocular Surface Society's Dry Eye WorkShop) established a comprehensive definition that is now widely adopted in clinical studies.

According to the TFOS DEWS II protocol, dry eye is defined as:

“A multifactorial disease of the ocular surface characterized by a loss of homeostasis of the tear film, and accompanied by ocular symptoms, in which tear film instability and hyperosmolarity, ocular surface inflammation and damage, and neurosensory abnormalities play etiological roles.”

This definition brings clarity to the complexity of dry eye, recognizing it as a multifactorial disease—meaning that it doesn’t have a single cause but rather arises from a combination of factors that affect the delicate balance of the tear film and the overall health of the ocular surface.TFOS DEWS II Report Executive Summary

The Key Components of Dry Eye According to TFOS DEWS II

1. Loss of Tear Film Homeostasis: The tear film is essential for protecting and lubricating the surface of the eye. When the tear film is disrupted—whether due to insufficient tear production or excessive evaporation—the delicate balance of the ocular surface is compromised.  TFOS DEWS II Definition and Classification Report - PubMed
2. Tear Film Instability: This refers to the breakdown of the tear film, which can lead to irritation, blurred vision, and discomfort. Instability causes the tears to evaporate more quickly, leaving the eye surface dry and exposed. Biological functions of tear film - PubMed
3. Hyperosmolarity: An imbalance in the concentration of salts and proteins in the tear film (hyperosmolarity) can lead to inflammation and damage to the ocular surface, causing discomfort and irritation. Protection against corneal hyperosmolarity with soft-contact-lens wear - PubMed
4. Ocular Surface Inflammation and Damage: Chronic dryness can result in inflammation of the eye's surface, which can cause long-term damage to the cornea and conjunctiva. Dry Eye Management: Targeting the Ocular Surface Microenvironment - PubMed
5. Neurosensory Abnormalities: Dry eye symptoms can also be influenced by abnormalities in the sensory nerves of the eye. In some cases, the nerves may become hypersensitive, contributing to the sensation of discomfort or pain, even when there’s minimal damage to the ocular surface. Defining Dry Eye from a Clinical Perspective - PubMed

The Scope of the Problem: Who is Affected?

The TFOS DEWS II definition is important because it provides a more nuanced understanding of dry eye disease, yet it also leads to some debate in terms of the actual number of people affected. Using this definition, research suggests that around 8% of Americans suffer from dry eye disease. However, that number can be misleading when considering the factors involved.

Historically, dry eye disease was considered more common among women over 50. However, the definition also acknowledges that dry eye is no longer confined to older adults—in fact, there’s growing evidence that younger populations are increasingly being diagnosed with the condition. The rise in digital device use, environmental factors, and changes in lifestyle are contributing to this increase, with younger adults experiencing dry eye symptoms at rates similar to or even exceeding those of older age groups.       

Risk Factors for Dry Eye Disease

While anyone can develop dry eye disease, certain factors increase the likelihood of experiencing symptoms. The TFOS DEWS II definition helps identify those at higher risk:

• Age: Older adults are more likely to develop dry eye, particularly women over the age of 50, as hormonal changes (such as menopause) can affect tear production.
• Gender: Women are more commonly affected than men, possibly due to hormonal fluctuations related to pregnancy, menopause, or the use of birth control.
• Environmental Factors: Exposure to dry, windy, or smoky environments can exacerbate tear film evaporation and irritation, increasing the risk of dry eye. Influence of Environmental Factors with Clinical Signs and Symptoms in the Management of Dry Eye Disease
• Health Conditions: Co-existing conditions like autoimmune diseases (e.g., Sjögren's syndrome), diabetes, or rosacea can contribute to dry eye by either disrupting tear production or causing inflammation in the ocular surface.
• Medications: Certain medications, including antihistamines, decongestants, antidepressants, and blood pressure medications, can reduce tear production and worsen dry eye symptoms.  Is there a relationship between the severity of disease in major depressive disorder patients and dry eye disease? - PubMed
• Contact Lenses: Extended use of contact lenses or improper care can impair tear production and lead to discomfort and dryness, making contact lens wearers more susceptible to dry eye disease. Investigation of Delefilcon A Contact Lenses for Symptomatic Daily Disposable Contact Lens Wearers with Dry Eye Disease: A Prospective Comparative Study
• Eye Surgery: Procedures like LASIK and other refractive surgeries can temporarily reduce tear production and cause dryness, particularly in the first few months post-surgery. 
• Lifestyle Factors: Smoking, excessive screen time, and inadequate sleep are all modern-day contributors to dry eye disease. The increased use of digital devices has been particularly noted as a significant factor, as prolonged screen use reduces blink rate and can lead to incomplete blinks, further aggravating the condition. Dry eye disease and retinal nerve fiber layer changes in chronic smokers - PubMed

Why the Debate?

The TFOS DEWS II definition of dry eye disease has been instrumental in defining and understanding this multifactorial condition, but it is not without its controversies. One significant point of debate is the 8% prevalence rate that this definition suggests. Many researchers and clinicians believe this figure may underestimate the true scope of the issue, particularly in younger populations. Dry eye disease exists on a spectrum—ranging from mild irritation to severe, chronic discomfort—and symptoms can vary significantly from person to person. This variability means that many individuals with early-stage dry eye symptoms may not seek professional care, especially if the symptoms are mild or intermittent. As a result, the reported prevalence rate may not fully reflect how widespread dry eye truly is. Dry eye disease in the young: A narrative review - PubMed

Additionally, the multifactorial nature of dry eye—where multiple factors overlap and interact—makes it difficult to identify a single cause or universal treatment. The complex nature of the condition means that dry eye often requires a personalized approach, one that takes into account the individual’s health, lifestyle, and environmental factors. It’s clear that dry eye is not a one-size-fits-all condition, and its increasing prevalence highlights the importance of tailored treatments and preventative care.

Peeq Pro's Perspective: Why It Matters

At Peeq Pro, we recognize that dry eye disease is not just a passing nuisance but an increasingly severe problem that many people, including doctors themselves, have not yet fully grasped. We believe that the impact of dry eye is being underestimated, and it’s not always taken as seriously as it should be. As research into meibomian gland dysfunction (MGD)—a precursor to dry eye—continues to evolve, one staggering statistic emerges: 73% of Americans suffer from MGD. That’s a huge portion of the population at risk of developing dry eye disease, and the numbers are only projected to grow. By 2030, more than 30 million Americans are expected to struggle with this painful, vision-impairing condition.

Modern lifestyle factors, particularly the increased use of digital devices and environmental pollutants, have a direct impact on eye health, and in many cases, new technologies and habits haven’t taken into account their effects on the delicate skin around the eyelids. Over time, these factors contribute to the accumulation of biofilm—a sticky layer of bacteria, oils, and debris that can further exacerbate symptoms of dry eye and lead to additional concerns like blepharitis and meibomian gland dysfunction. DEBS - a unification theory for dry eye and blepharitis - PubMed

At Peeq Pro, we believe that this growing crisis requires action—and that’s why we’re committed to addressing the root causes of dry eye through simple, effective, and accessible routines that focus on long-term eye health. We’re not just introducing another beauty tool; we’re on a mission to provide practical solutions that improve eye comfort and vision for people at all stages of dry eye. Our goal is to empower individuals to take control of their ocular health, with products that help prevent dry eye from developing or progressing further.

Peeq Pro’s Mission: Prioritizing Eye Health

Why does it matter? The need for specialized eye care is real. Too often, cosmetic products, cleansers, and even everyday skincare routines neglect the sensitive area around the eyes. Traditional beauty tools may contribute to the buildup of dirt, oil, and bacteria, but they fail to address the root causes of eyelid hygiene and eye health. Peeq Pro is breaking this barrier. We believe your eyes deserve dedicated care—not just in terms of beauty, but as part of a broader health routine.

By focusing on eyelid hygiene and tackling meibomian gland dysfunction, we help prevent the conditions that can lead to or worsen dry eye disease. Our products, like the Peeq Pro Eyelid Cleanser and the Waiva Device, are designed to dislodge debris and biofilm while also reducing inflammation and bacteria. We’re providing a safe, gentle, and effective way to maintain clean, healthy eyelids, which ultimately supports better tear production, comfort, and overall eye health.  Waiva Eyelid Cleaning System – Peeq Pro

Eyes Are Windows to the World

We all know the importance of healthy eyes—they are the windows to our world. And yet, they often don’t receive the attention they deserve. At Peeq Pro, we’re on a mission to change that by revolutionizing how we care for our eyelids and overall ocular health. Our products aren’t just for beauty—they are vital for the health of your eyes and comfort in your daily life. Through easy-to-follow, tailored routines, Peeq Pro is helping people of all ages take proactive steps to improve their eye health and quality of life. Foaming Eyelid & Facial Cleanser for Eyelid Hygiene – Peeq Pro 

As we continue to build awareness about dry eye disease and its prevalence, we hope to inspire everyone to make their eye health a priority. Dry eye is no longer just a condition that affects the elderly; it’s a condition that can impact anyone—especially in our increasingly digital world. By addressing eyelid hygiene and supporting tear film stability, we can keep our eyes clear, bright, and healthy. Join us in our journey to improve eyelid health and eye comfort, one gentle cleanse at a time.