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Dry Eye Disease

What Is Dry Eye Disease? More Than Dryness

Dry eye is a real, treatable disease of the tear film — not simply “dry eyes.” Understanding what it is, the form you have, and what’s driving it is the first step toward finding the specific cause and lasting relief.

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Overview

A Disease, Not Just “Dry Eyes”

“Dry eye” sounds minor — a passing nuisance you fix with a bottle of drops. In reality, dry eye disease is a recognised, chronic medical condition of the ocular surface. It happens when the thin film of tears that protects the front of your eye becomes unstable, insufficient, or unhealthy — and the result is a cycle of irritation and inflammation that, left alone, tends to feed itself.

The international clinical standard that defines it, the TFOS DEWS II framework, describes dry eye disease as a multifactorial disease of the ocular surface marked by a loss of tear-film stability, with inflammation and damage to the surface of the eye playing a central role. In plain terms: it isn’t just that your eyes feel dry — something specific has gone wrong with the system that keeps them moist, and that something can be identified and treated.

This page explains what dry eye disease actually is — how your tears are built, the three main types of the disease, what causes it, whether it’s permanent, and how it’s properly diagnosed and treated. If you want to understand the symptoms you feel day to day and when they warrant a specialist, see our companion guide to dry eye symptoms.

Why it’s a disease, not just dryness

Calling it a “disease” isn’t dramatic language — it’s clinically accurate, and it matters. Dry eye disease is progressive in its most common form: the tiny oil glands that keep your tears from evaporating can gradually shrink and disappear if the underlying problem isn’t addressed. It also drives inflammation that damages the surface of the eye, which in turn worsens the dryness — a self-reinforcing loop.

Understanding dry eye as a disease reframes the goal. The aim isn’t to keep topping up drops forever, but to find what’s actually breaking down in your tear film and treat that cause — so the loop is interrupted rather than endlessly managed at the surface.

How tears work

Your Tears Are Built in Three Layers

To understand dry eye disease, it helps to know that your tears are not just water. Every time you blink, you spread a remarkably engineered three-layer film across the front of your eye. Each layer has a job, and dry eye disease is almost always a breakdown in one of them.

Outer layer

Oil (lipid)

A thin film of oil produced by the meibomian glands in your eyelids. It seals the surface and stops your tears evaporating too quickly. When these glands block or fail, tears evaporate fast — the most common cause of dry eye.

Middle layer

Water (aqueous)

The bulk of the tear film, produced by the lacrimal glands. It hydrates the surface, washes away debris, and carries nutrients and protective proteins. Too little of it leaves the eye under-supplied.

Inner layer

Mucin (mucus)

A sticky base layer that lets the watery tears spread evenly and cling to the eye’s surface. Without it, tears bead up and slide off instead of forming a smooth, even coat.

When all three layers are healthy and balanced, the surface of your eye stays smooth, clear, and comfortable — and your vision is sharp, because this film is the very first surface light passes through. Dry eye disease begins when that balance is lost. Knowing which layer has broken down is what points toward the right type of dry eye, and the right treatment.

The three types

The Three Types of Dry Eye Disease

Dry eye disease is not one condition but a family of them, grouped by which part of the tear film has failed. Identifying the type is the whole point of a proper assessment, because the types respond to different treatments. Most people fall into one of three categories.

TypeWhat’s going wrongHow common & what it’s linked to
Evaporative (MGD)The oil layer breaks down — usually from meibomian gland dysfunction — so tears evaporate too fast even when tear volume is normal.The most common form, accounting for the majority of cases. Linked to gland blockage, blepharitis, rosacea, screen use and age.
Aqueous-deficientThe eye simply doesn’t produce enough of the watery middle layer, so the surface is under-supplied.Less common than evaporative. Linked to ageing, autoimmune conditions such as Sjögren’s syndrome, and certain medications.
MixedA combination of both — too little tear volume and an oil layer that lets tears evaporate. Both pathways are active at once.Very common in practice. Many long-standing or moderate-to-severe cases turn out to be mixed, which is why a full workup matters.

Evaporative dry eye deserves a closer look, because it’s both the most common and the most under-recognised. Its driver, meibomian gland dysfunction (MGD), is a gradual blockage and decline of the tiny oil glands lining your eyelids. Many people have it for years before it’s named. You can read more on our dedicated meibomian gland dysfunction and aqueous-deficient dry eye pages, and on blepharitis, the lid inflammation that so often travels with it.

Causes & risk factors

What Causes Dry Eye Disease?

Dry eye disease rarely has a single cause. More often, several factors stack up over time until the tear film can no longer keep up. Knowing your own risk factors helps explain why the disease developed — and which ones can be changed.

  • Age — tear quality and volume naturally decline over the years, which is why dry eye becomes more common with age
  • Screens and reduced blinking — focusing on a monitor or phone cuts your blink rate by half or more, so the tear film isn’t refreshed and the oil isn’t expressed
  • Hormonal change — shifts around menopause, and hormonal therapies, alter tear production; women are affected more often than men
  • Medications — antihistamines, decongestants, antidepressants, some blood-pressure drugs and acne medication (isotretinoin) all reduce tear production or harm the oil glands
  • Autoimmune disease — conditions such as Sjögren’s syndrome, rheumatoid arthritis and rosacea attack or inflame the glands that make your tears
  • Eye surgery — dry eye is common, and usually temporary, after cataract or laser vision correction
  • Environment — dry, heated indoor air in winter, air conditioning, wind, and contact-lens wear all speed up evaporation

Some of these you can modify — screen habits, humidity, lens wear. Others, like age, autoimmune disease, or a medication you need, you can’t. That’s exactly why dry eye is managed rather than simply “fixed,” and why the treatment plan is built around your particular mix of causes rather than a generic protocol.

Is it serious or permanent?

Is Dry Eye Permanent? Can It Be Cured?

Here’s the honest answer patients deserve: for most people, dry eye disease is a chronic condition that is managed rather than permanently “cured.” That isn’t bad news. With the right diagnosis and treatment, the large majority of patients reach a point where their eyes are comfortable, their vision is stable, and the disease is quietly under control — it simply needs ongoing care, the way many chronic conditions do.

What changes the outcome most is timing. In evaporative dry eye, the oil glands can shrink and drop out permanently if the disease runs unchecked for years — and glands that are already lost cannot be regrown. But glands that are blocked yet still viable can often be revived, and the inflammation driving the disease can be calmed. This is the reversibility worth acting on: the earlier the disease is properly identified, the more of your tear-producing structures can be protected, and the better the long-term trajectory. Early specialist intervention genuinely changes how dry eye plays out.

Most dry eye is uncomfortable but not dangerous to your sight. Severe, untreated dry eye can, over time, damage the surface of the cornea and — rarely — lead to scarring or infection that threatens vision. Some symptoms, though, are not dry eye at all but signs of a more serious eye problem that needs urgent attention:

Red flags — seek urgent eye care

  • Sudden loss or change in vision in one or both eyes
  • Severe eye pain — intense pain rather than a gritty ache
  • Halos or rings around lights, especially with pain or nausea
  • Thick, coloured, or pus-like discharge from the eye
  • A sudden shower of new floaters or a fixed flash of light
  • Contact-lens wearers: any pain, redness, or blur while wearing or after removing lenses — this can signal a sight-threatening infection and must never be ignored

Short of those emergencies, the practical signal that dry eye needs a specialist is simple: your symptoms persist or keep returning despite consistent drops and lid care. That’s not a failure on your part — it usually means the underlying cause hasn’t been found and treated. For a fuller guide to the warning signs and when to escalate, see our dry eye symptoms page.

How it’s diagnosed

How Dry Eye Disease Is Properly Diagnosed

You cannot treat what you haven’t measured. The difference between guessing at drops and treating the disease is a proper diagnostic workup — one that looks directly at the tear film and the glands behind it. As a dedicated dry eye centre, UDEI works alongside referring optometrists across the Greater Toronto Area, taking on the advanced diagnostics and refractory cases that go beyond routine care. These are the tools that find the cause an over-the-counter drop can’t.

Meibography — Direct Gland Imaging

This is the single biggest differentiator in a specialist dry eye assessment. Using infrared meibography, we capture high-resolution images of the oil glands hidden inside your eyelids — structures invisible on a routine exam. The images show which glands are healthy and full-length, which are blocked but still viable, and which have already shrunk or dropped out. Because evaporative dry eye is the most common type, seeing the glands directly often explains the whole picture — and tells us how much is still worth saving.

Tear Osmolarity

We measure the salt concentration of your tears. Elevated osmolarity is one of the most specific objective markers of dry eye disease — it reveals an unstable, over-concentrated tear film even when the eye looks normal, and gives us a number we can track to confirm treatment is working.

MMP-9 Inflammation Testing

A rapid in-office test detects MMP-9, a marker of ocular surface inflammation. A positive result tells us inflammation is part of what’s driving the disease — which directly changes the plan, often toward anti-inflammatory therapy that lubricating drops alone can’t provide.

Tear Break-Up Time & Surface Staining

We time how quickly your tear film destabilises between blinks and use dyes to reveal where the surface of the eye has become dry and damaged. Together these establish how unstable the film is and how much surface injury the disease has already caused.

Classification & Personalised Plan

We bring the findings together to classify your dry eye — evaporative, aqueous-deficient, or mixed — and grade its severity using the TFOS DEWS II framework. Then we show you your own images and numbers, and build a plan around your specific cause. No two patients are the same, and neither are their treatment plans.

Treatment overview

How Dry Eye Disease Is Treated

There is no single cure for dry eye disease, but for most people it can be controlled very effectively. The goal is to treat the specific cause your assessment uncovers — and to do it in the right order.

Treatment at UDEI is sequenced, not stacked. We start with the simplest measures that fit your diagnosis and escalate only when the evidence calls for it. More expensive does not mean more effective — the right treatment is the one matched to your cause, and we’ll explain the options so you can decide.

Home Care Foundation

Warm compresses, lid hygiene, preservative-free drops, omega-3 supplementation, and screen-break habits. For mild disease this is often enough — and it’s the foundation that makes every other treatment work better.

First step / all severities

UltraView DEL™ (IPL)

Our proprietary intense pulsed light therapy targets the inflammation and gland dysfunction behind evaporative dry eye — addressing the cause that drops can’t reach.

Evaporative / MGD
Learn about UltraView DEL →

LipiFlow Thermal Pulsation

Controlled heat and gentle pressure unclog blocked oil glands and restore meibum flow — for evaporative dry eye where glands are still expressible.

Evaporative / MGD
Learn about LipiFlow →

BlephEx Lid Treatment

Professional debridement clears bacterial biofilm and debris from the lid margin, easing the blepharitis that so often coexists with dry eye.

Dry eye + blepharitis

Punctal Plugs

For aqueous-deficient dry eye, tiny plugs conserve your natural tears by slowing their drainage — keeping more moisture on the eye for longer.

Aqueous-deficient

Ongoing Maintenance

Because dry eye is chronic, results are sustained with a home regimen and periodic follow-up. We design a routine you can actually keep and track progress with objective measurements.

Maintenance

Most patients do best with a combination matched to their type and severity, rather than a single approach. For refractory or advanced disease — including severe aqueous deficiency and autoimmune-related dry eye — additional options such as hemoderivative (autologous serum) drops may be considered. We’ll guide you through the choices and adjust as your eyes respond.

Connected care

Dry Eye Within a Connected Network

Dry eye disease rarely exists in isolation. As part of U Vision Group, UDEI is connected to a full network of specialists — and we work hand in hand with referring optometrists rather than in place of them. If your dry eye is tied to something else, your care moves with you, without starting over:

Start with your symptoms. If you’re trying to make sense of what you feel day to day — and when it warrants a specialist — our companion guide to dry eye symptoms walks through it. From there, the meibomian gland dysfunction, aqueous-deficient dry eye and blepharitis pages go deeper on each form.

Dry eyes with contact lenses or screens? Lens-related and digital dryness often improve with a change in lens material or wear schedule. We coordinate with the optometrists at U Optical on lens fit and specialty options alongside your dry eye treatment.

Dry eye after cataract surgery, or another condition behind your symptoms? Post-surgical dryness is common and treatable, and a full ocular surface workup sometimes reveals pathology beyond dry eye. We work closely with the surgeons at Uptown Eye Specialists for co-managed, specialist-led care.

Considering laser vision correction? Stabilising dry eye first protects your laser outcome. Pre-treatment at UDEI is part of the shared-care protocol with U Eye Laser Cosmetic.

Need home care products? U Shoppe stocks clinician-selected drops, heated masks, lid wipes, and omega-3 supplements matched to your treatment plan.

For referring optometrists: UDEI is a dedicated dry eye centre and a referral partner. We co-manage advanced and refractory dry eye and report back on every patient, so you stay involved in their care. Learn how to refer at uptowneye.ca/referring-doctors.

Common questions

Frequently Asked Questions

Dry eye disease is a chronic medical condition of the ocular surface in which the tear film — the thin, three-layer film that coats the front of your eye — becomes unstable, insufficient, or unhealthy. The result is irritation, inflammation, and symptoms such as burning, grittiness, fluctuating vision, and even watery eyes. It is far more than “dry eyes”: the international TFOS DEWS II framework defines it as a multifactorial disease with loss of tear-film stability and surface inflammation at its core.

Because it is a disease rather than a passing nuisance, it has identifiable causes and types — and it responds best to treatment aimed at the specific cause, not just topping up drops at the surface.

They are the two main types of dry eye, and the difference is which part of the tear film fails. In evaporative dry eye — the most common form — tear volume can be normal, but the oil layer has broken down (usually from meibomian gland dysfunction), so tears evaporate too fast. In aqueous-deficient dry eye, the eye simply doesn’t produce enough of the watery middle layer, so the surface is under-supplied; it’s often linked to age, autoimmune conditions such as Sjögren’s syndrome, and certain medications.

Many people actually have a mixed picture, with both problems at once. The distinction matters because the two types respond to different treatments — which is exactly what a specialist workup is designed to sort out.

For most people, dry eye disease is a chronic condition that is managed rather than permanently “cured.” That isn’t bad news: with the right diagnosis and treatment, the large majority of patients reach a point where their eyes are comfortable and the disease is quietly under control. It simply needs ongoing care, the way many chronic conditions do.

Timing matters most. In evaporative dry eye, oil glands that are blocked but still viable can often be revived, while glands already lost cannot be regrown. So the earlier the disease is properly identified, the more of your tear-producing structures can be protected — and the better the long-term outlook. Early specialist intervention genuinely changes how dry eye plays out.

Dry eye disease rarely has a single cause; usually several factors stack up over time. The most common driver is meibomian gland dysfunction, where the eyelid oil glands block and tears evaporate too fast. Other contributors include ageing, prolonged screen use (which halves your blink rate), hormonal change around menopause, and medications such as antihistamines, decongestants, antidepressants and some acne drugs.

Autoimmune conditions such as Sjögren’s syndrome and rosacea, eye surgery, and dry or windy environments also play a role. Some of these you can change — screen habits, humidity, lens wear — and some you can’t, which is why treatment is built around your particular mix of causes.

For the vast majority of people, dry eye does not cause blindness, and it is not typically sight-threatening. It is, however, a real disease that can erode your comfort, your vision quality, and your daily life. Left untreated and severe, it can damage the surface of the cornea over time and, in rare cases, lead to scarring or infection that can threaten vision — which is the real reason not to simply “live with it.”

Some symptoms are warning signs of something other than dry eye and need urgent care: sudden vision loss, severe eye pain, halos around lights, thick or coloured discharge, a sudden shower of floaters, or any pain and blur in a contact-lens wearer. When in doubt, get assessed promptly rather than reaching for drops.

Eye drops are useful, but they manage rather than cure dry eye disease. Over-the-counter artificial tears supplement your tear film and soothe symptoms for a while — a sensible first step for mild cases. What they don’t do is fix the underlying reason your eyes are dry. If the cause is blocked oil glands (the most common form), drops sit on top of the problem rather than treating it.

That’s why so many people feel stuck on a cycle of drops that never quite work. A specialist assessment identifies the actual cause — using tools like meibography and osmolarity — so treatment can target the source. That’s how lasting relief usually happens, rather than from another bottle of drops.

A proper diagnosis looks directly at the tear film and the glands behind it, rather than guessing from symptoms alone. The lead tool is meibography — infrared imaging that shows the oil glands hidden inside your eyelids, revealing which are healthy, blocked, or already lost. Tear osmolarity measures how concentrated and unstable your tears are, and an MMP-9 test detects ocular surface inflammation.

We add tear break-up time and surface staining to gauge stability and any damage, then classify your dry eye as evaporative, aqueous-deficient, or mixed and grade its severity using the TFOS DEWS II framework. These advanced diagnostics are part of what a dedicated dry eye centre offers alongside your optometrist’s routine care.

Dry eye disease is common and becomes more so with age, but it can affect anyone. Your risk is higher if you spend long hours on screens, are over 50, are going through or past menopause, take medications that reduce tear production, wear contact lenses, or live and work in dry, heated, or air-conditioned environments — a particular issue through Canadian winters.

Risk is also raised by autoimmune conditions such as Sjögren’s syndrome and rheumatoid arthritis, by rosacea, and by previous cataract or laser eye surgery. Having one or more of these doesn’t mean you’ll develop dry eye, but if you also have persistent symptoms, they’re worth having assessed rather than waiting out.

OHIP covers a standard eye examination at certain intervals depending on your age and medical history. However, advanced dry eye diagnostics — such as meibography, tear osmolarity, and MMP-9 inflammation testing — and in-office treatments such as UltraView DEL, LipiFlow, and BlephEx are specialised services that are not covered by OHIP.

Many extended health insurance plans cover some prescription drops and a portion of in-office treatments, so it’s worth checking your benefits. UDEI provides itemised receipts you can submit, and we’ll explain costs clearly before any treatment so you can decide.

UDEI is a dedicated dry eye centre and a referral partner for optometrists across the Greater Toronto Area. We welcome patients with moderate-to-severe, refractory, or post-surgical dry eye for advanced diagnostics and treatment, and we report back on every patient so you stay involved in their care.

To refer, fax a referral to 416-292-0331, call our team at 416-292-0334, or email info@udei.ca. You can also learn more about our professional relations and co-management pathways at uptowneye.ca/referring-doctors.

Research-led care

Evidence Behind Our Dry Eye Treatment

UDEI’s clinicians don’t just follow the evidence on dry eye disease — they help generate it. Our work on intense pulsed light, regenerative drops, and post-surgical and autoimmune dry eye has been published in peer-reviewed ophthalmology journals, and it shapes the way we diagnose and treat the patients we see.

IPL / UltraView DEL™

Safety and Efficacy of BroadBand Intense Pulsed Light Therapy for Dry Eye Disease with Meibomian Gland Dysfunction

Clinical Ophthalmology, 2021 · DOI 10.2147/OPTH.S331289

Murtaza F; Toameh D; Al-Habib S; Maini R; Chiu HH; Tam ES; Somani S — including U Vision Group author Dr. Raj Maini.

View on PubMed →
Regenerative therapy

Autologous Platelet-Rich Plasma Drops for Evaporative Dry Eye Disease from Meibomian Gland Dysfunction

Clinical Ophthalmology, 2022 · DOI 10.2147/OPTH.S367807

Murtaza F; Toameh D; Chiu HH; Tam ES; Somani S — including U Vision Group authors Dr. Sohel Somani and Dr. Eric S. Tam.

View on PubMed →

Health Care Utilization, Prevalence, and Risk Factors of Dry Eyes After Cataract Surgery

Canadian Journal of Ophthalmology, 2024 · DOI 10.1016/j.jcjo.2024.08.011 · Krance SH; Hatamnejad A; Uddin R; Somani S; Tam E; Murtaza F; Chiu HH

View on PubMed →

Sjögren’s Syndrome-Associated Dry Eye: Impact on Daily Living and Adherence to Therapy

Journal of Clinical Medicine, 2022 · DOI 10.3390/jcm11102809 · Michaelov E; McKenna C; Ibrahim P; Nayeni M; Dang A; Mather R

View on PubMed →

Authored by U Vision Group clinicians. Citations are provided for educational and transparency purposes; individual results vary, and any treatment decision should follow a personalised assessment.

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A comprehensive dry eye assessment identifies the specific type and cause of your dry eye disease — so treatment targets the source, not just the symptoms. Est. 2006, UDEI has been helping patients across the Greater Toronto Area find lasting relief from dry eye disease.

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