About our disease
What is “dry eye”?
This phrase is used for a spectrum of experiences:
Unfortunately, “dry eye” has become an overused, inaccurate and trivializing term.
This makes it harder for people with severe dry eye to get real help.
In the medical world, “dry eye” is an umbrella term.
“Dry eye” is not a single disease or diagnosis.
“Dry eye” is usually an intersection of one or more ocular surface diseases (OSD) and ocular surface pain (OSP) i.e. eye discomfort in its various forms.
“Dry eye” is commonly used to refer to the clinical signs and/or the symptoms of many diseases and conditions, each with its own separate underlying causes, regardless of severity. Sometimes these diseases or conditions remain undiagnosed for years because symptoms are mild and can be lumped under the convenient heading of “dry eye”.
The ocular surface diseases that fall in this “dry eye bucket” may involve the moisture-secreting (lacrimal) glands above the eye, the oil-secreting (meibomian) glands in our eyelids, our blink function, our tear drainage (nasolacrimal) system, or the underside of the eyelids, or the entire surface of the eye. They may also involve damage to the nerves in the surface of the eye (cornea), resulting in intense chronic pain even in the absence of any obvious sign of disease at all. There may be allergies or inflammatory conditions or dermatological conditions involved.
Don’t settle for a diagnosis of “dry eye”. Ask for more details. You may need a referral to a specialist.
OSD & OSP are a 21st century trend now affecting all generations, even kids.
In the scientific world, the idea of “dry eye” is evolving and broadening.
Once upon a time, “dry eye” was understood literally: no tears.
You were considered to have “dry eye” if your lacrimal glands (the ones that secrete the watery part of our tears) failed to do their job, so you literally could not make tears. “Dry eye” meant lacrimal insufficiency, also called Aqueous Deficient Dry Eye (ADDE). Sometimes it was referred to by the Greek term xerophthalmia (dry + eye). It was not very common.
In the last 30 years, everything has changed - because our eyes are changing.
30 years ago, we weren’t all staring at screens all day in air-conditioned offices. Most of us weren’t using as many medications on a daily basis back then, and not very many of us had eye surgeries at a young age. Our diet has continued to evolve along with our lifestyles. For these and other reasons, more and more people are experiencing eye discomfort on a regular basis and seeking help for it, and many of them really do have something wrong with their tears.
The definition of dry eye is now very, very broad.
A key part of the response from the scientific world has been to broaden the definition of dry eye. Scientists started studying the tear film - that overlooked but essential thin liquid layer without which we cannot see. And they started finding all different sorts of things that go wrong with the tear film in different ways, not just from lacrimal gland failure. So, in 1995, the National Eye Institute expanded the definition to include excessive evaporation of tears, and in 2007, the TFOS Dry Eye Workshop expanded it again to include vision disturbance, inflammation and tear osmolarity, and then again in 2017 TFOS DEWS II redefined it again to the point where it now pretty much covers anything and everything that might go wrong with the tear film in some way, shape or form:
“Dry eye is 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 is a good thing, and a bad thing.
Good, because these conditions are affecting so many people. We have to be able to pull everyone with related issues somehow under the same heading in order to properly assess “dry eye” as a public health problem.
And also bad, because when you call all of the different things by the same name, patients may all get treated alike - even if their medical condition and needs are completely different from each other.
How many people have dry eye in the USA?
Somewhere between 16 million and 50 million.
Wait… what?
Estimated prevalence for most diseases tends to be considerably more precise than that.
But… for the last 20 years of dry eye research, disease definitions have wobbled all over the map. We’re not just talking apples and oranges but papayas and dragonfruit.
Some studies measure dry eye by symptoms, some by clinical signs, some by both. Some measure Schirmer scores, or corneal staining, or TBUT, or some other clinical test. Some use the OSDI symptom survey, some use SPEED, some use unvalidated surveys or just make up their own.
The dry eye world is sorely in need of standardized measures, especially for patient symptoms. This is an important part of Dry Eye Foundation’s advocacy platform.
And what is dry eye really like?
In a nutshell:
It’s very uncomfortable. Scientific studies compare the quality of life impact of DED to that of angina (chest pain from coronary artery disease).
It affects common daily activities, like work, device use, outdoor activities, and reading.
It’s not easily remedied, despite a proliferation of over-the-counter and prescription remedies as well as a vast array of specialty treatments.
Check out our recent survey results to learn more about how DED affects our lives:
The outsized impact of DED on our community’s lives is why we started Dry Eye Foundation.
Our mission is to improve quality of life for people with Dry Eye Disease.
dry eye disease
Let’s start by changing the language of dry eye.
“Dry eye” is actually a two-part problem:
Ocular Surface Disease
Ocular Surface Disease is the umbrella term for all of the different types of medical conditions affecting the surfaces of the eye and eyelids, including conditions traditionally referred to as "dry eye” and also other conditions such as allergic conjunctivitis.
We believe all people with OSD deserve a specific diagnosis. “Dry eye” is a start, but it’s not a diagnosis.
Accurate diagnosis is the first step towards solutions.
Ocular Surface Pain
Ocular Surface Pain is all of the symptoms of ocular discomfort, including those that people may not normally describe using the word “pain”. These include sensations like burning, stinging, grittiness, aching, heaviness, irritation, itchiness, light sensitivity, and many more.
OSP symptoms are the most common reason why people visit eye doctors, yet this condition is not usually defined and specifically addressed. Again, accurate diagnosis is the first step towards solutions.