Dry eye occurs when there is an insufficient amount of tear film or when its composition is disrupted, which leads to discomfort and potential damage to the eye's surface. The tear film, which consists of 3 distinct layers, is essential for keeping the eyes moist, clean, and clear.
What is a dry eye?
Under normal conditions, our eyes are constantly making tears to keep the surface of the eye moist. Although tears are typically considered as a simple, homogeneous substance, we have a complex tear film that keeps our eyes healthy and comfortable, which consists of three distinct layers. Every time we blink, the tear film coats the surface of the eye, which helps to keep them clean and clear. If insufficient amounts of the tear film or its composition is off, dry eyes can occur.[1]
What are the main signs and symptoms of dry eye?
Symptoms of dry eyes include redness or irritation, which is especially evident in the wind, stinging or burning sensation in the eyes, blurred vision, can be especially noticeable when reading, a scratchy or gritty feeling, that feels like sand in the eye, presence of strings of mucus in and around the eyes, pain and discomfort while wearing contact lenses, increased amounts of tears in the eye.
How is dye eye diagnosed?
Dry eye is diagnosed by an ophthalmologist, who will start with an eye exam to look at the eyelids and surface of the eye. Ophthalmologists may perform different tests to diagnose dry eyes including the following:
- Examine amount of tears that your eyes make
- Determine how long it takes tears to dry up
- Examine eyelid structure
What are some of the main medical treatments for dry eye?
Artificial tears are one treatment for dry eyes, which are available without a prescription and can be administered multiple times per day.
Prescription eye drop medications may also be recommended to help the eyes make more of their own tears.
Newer treatments are also available (or are being developed) that specifically target the underlying causes of dry eyes.[2]
Blocking tear ducts is another treatment that may be recommended by an ophthalmologist.
Have any supplements been studied for dry eye?
Pycnogenol, a patented formulation of pine bark extract, has shown promise for alleviating dry eyes in patients with Sjogren’s disease, a common autoimmune condition in women that causes dry eyes and dry mouth. The mechanism of action isn’t clear but may be due to the anti-inflammatory effects of pycnogenol.
Fish oil and omega 3 fatty acids have also shown some promise for providing relief to dry eyes with one study showing a 17% lower risk of dry eye compared to a placebo.[3] As with pycnogenol, the mechanism of action is not well understood, but likely involves the anti-inflammatory activity of omega-3 fats.
How could diet affect dry eye?
Good nutrition helps to keep the eye healthy overall and may reduce the risk of eye diseases such as dry eye. Overall, getting plenty of leafy green vegetables along with yellow, orange, and other colorful fruits and vegetables will help to keep the eyes healthy.[4]
Dietary patterns that are good for the heart may also be good for the eyes, since the eyes rely on tiny arteries to deliver oxygen and nutrients. As with the heart, keeping blood vessels healthy will help to keep the eyes healthy.
Are there any other treatments for dry eye?
The most common non-medical treatments for dry eye, such as artificial tears and lubricating eye drops are available over the counter, without a prescription. Although this is a good place to start if you have infrequent issues with dry eyes, it is important to see a doctor if symptoms persist or become worse.
What causes dry eye?
Hormonal changes during aging can be a cause of dry eye. Although both men and women can get dry eye, it tends to be more common in women, especially after menopause. There are many other causes of dry eye, which including autoimmune diseases such as rheumatoid arthritis, Sjogren's syndrome, and lupus, thyroid disease, smoke exposure, wind exposure, or being in a dry climate, prolonged activities that reduce blinking such as working at a computer screen for long periods of time, or reading, wearing contact lenses for an extended period of time, refractive eye surgery such as LASIK.
Additionally, medications that can cause dry eyes include diuretics, beta-blockers, antihistamines, sleeping pills, medications for anxiety or depression, and heartburn medications.[2]
Examine Database: Dry Eye
Research FeedRead all studies
Lutein might help with dry eyes
In this systematic review of 6 randomized controlled trials, lutein-containing supplements improved dry eye measures in the majority of the studies.
Risk factors for dry eye
Does supplementing with omega-3 fatty acids improve dry eye?
Lutein and zeaxanthin might protect eyes from electronic screen exposure
The effectiveness of a multicomponent supplement for improving dry eye
Frequently asked questions
What is a dry eye?
Under normal conditions, our eyes are constantly making tears to keep the surface of the eye moist. Although tears are typically considered as a simple, homogeneous substance, we have a complex tear film that keeps our eyes healthy and comfortable, which consists of three distinct layers. Every time we blink, the tear film coats the surface of the eye, which helps to keep them clean and clear. If insufficient amounts of the tear film or its composition is off, dry eyes can occur.[1]
What are tears made out of?
Quick answer:
Tears are a complex mixture consisting of 3 distinct layers: the oily layer, which prevents rapid drying; the watery layer, which cleans the eye; and the mucus layer, which helps spread the watery layer and keeps the eyes moist. Each layer serves a specific purpose in maintaining eye health.
Most of us experience tears as a wet, salty substance that helps to keep the eyes moist. Rather than being a homogenous solution, tears are actually more complex, consisting of multiple layers, each serving a specific purpose.
The tear film consists of three distinct layers:
Oily layer: The oily layer is produced by the meibomian glands and makes up the outermost layer of the tear film. It helps to make the tear surface smooth and keeps them from drying too fast.
Watery layer: The watery layer is in the middle of the tear film and is produced by the lacrimal glands, located in the eye lids. This layer functions to clean the eye, washing away foreign particles.
Mucus layer: The mucus layer is the innermost layer of the tear film and is made in the conjunctiva —the clear tissue covering the white part of the eye and inside of the eyelids. This layer functions to help spread the watery layer over the surface of the eye and keep the eyes moist. Without the mucus layer, tears would not stick to the surface of the eye.
What are the main signs and symptoms of dry eye?
The main signs and symptoms of dry eye include redness or irritation, a stinging or burning sensation, blurred vision, a gritty feeling, the presence of mucus, discomfort with contact lenses, and increased tear production. These symptoms can be particularly noticeable in windy conditions or while reading.
Symptoms of dry eyes include redness or irritation, which is especially evident in the wind, stinging or burning sensation in the eyes, blurred vision, can be especially noticeable when reading, a scratchy or gritty feeling, that feels like sand in the eye, presence of strings of mucus in and around the eyes, pain and discomfort while wearing contact lenses, increased amounts of tears in the eye.
How is dye eye diagnosed?
Dry eye is diagnosed by an ophthalmologist through an eye exam that assesses the eyelids and the surface of the eye. Various tests may be performed to evaluate tear production, the duration that tears remain on the eye, and the structure of the eyelids.
Dry eye is diagnosed by an ophthalmologist, who will start with an eye exam to look at the eyelids and surface of the eye. Ophthalmologists may perform different tests to diagnose dry eyes including the following:
- Examine amount of tears that your eyes make
- Determine how long it takes tears to dry up
- Examine eyelid structure
What are some of the main medical treatments for dry eye?
The main medical treatments for dry eye include over-the-counter artificial tears, prescription eye drops to enhance tear production, and newer therapies that target the underlying causes. Additionally, blocking of the tear ducts may be recommended by an ophthalmologist.
Artificial tears are one treatment for dry eyes, which are available without a prescription and can be administered multiple times per day.
Prescription eye drop medications may also be recommended to help the eyes make more of their own tears.
Newer treatments are also available (or are being developed) that specifically target the underlying causes of dry eyes.[2]
Blocking tear ducts is another treatment that may be recommended by an ophthalmologist.
How can blocking tear ducts help with dry eyes?
Quick answer:
Blocking of the tear ducts can help alleviate dry eyes by preventing tears from draining away, thereby keeping more tears in the eye. This is typically achieved by inserting small silicone or gel plugs, known as punctal plugs, into the tear ducts.
Since tear ducts are part of the tear drainage system, blocking them may help to keep more tears in the eye. Tear ducts are blocked with small silicone or gel plugs (punctal plugs) that are inserted into tear ducts.[5]
Have any supplements been studied for dry eye?
Pycnogenol, a pine bark extract, has shown potential in alleviating dry eye, particularly in people with Sjögren’s syndrome, possibly due to its anti-inflammatory properties. Additionally, fish oil and omega-3 fatty acids may provide relief from dry eye; studies have indicated a reduced risk compared to a placebo, although the mechanisms are also not well understood.
Pycnogenol, a patented formulation of pine bark extract, has shown promise for alleviating dry eyes in patients with Sjogren’s disease, a common autoimmune condition in women that causes dry eyes and dry mouth. The mechanism of action isn’t clear but may be due to the anti-inflammatory effects of pycnogenol.
Fish oil and omega 3 fatty acids have also shown some promise for providing relief to dry eyes with one study showing a 17% lower risk of dry eye compared to a placebo.[3] As with pycnogenol, the mechanism of action is not well understood, but likely involves the anti-inflammatory activity of omega-3 fats.
How could diet affect dry eye?
Good nutrition, particularly through the consumption of leafy greens and colorful fruits and vegetables, supports overall eye health and may lower the risk of dry eye. Additionally, dietary patterns that are beneficial for heart health can also promote eye health by ensuring proper blood flow to the eyes.
Good nutrition helps to keep the eye healthy overall and may reduce the risk of eye diseases such as dry eye. Overall, getting plenty of leafy green vegetables along with yellow, orange, and other colorful fruits and vegetables will help to keep the eyes healthy.[4]
Dietary patterns that are good for the heart may also be good for the eyes, since the eyes rely on tiny arteries to deliver oxygen and nutrients. As with the heart, keeping blood vessels healthy will help to keep the eyes healthy.
Is there a connection between caffeine intake and dry eyes?
Quick answer:
Caffeine, because it is a diuretic, has been studied for its potential link to dry eye, but large cohort studies have found no association. Additionally, a randomized controlled trial indicated that caffeine may increase tear production, which suggests that it could have the opposite effect on dry eye.
Since caffeine is a diuretic (causes the body to lose water by expelling more fluid through the urine), it has been investigated as a potential cause of dry eyes. A couple of large, population-based cohort studies found no association between caffeine intake and dry eyes.[6][7] Moreover, an RCT in healthy individuals without dry eyes found that caffeine ingestion caused a significant intake in tear production, suggesting [8] that it may actually have the opposite effect.
Are there any other treatments for dry eye?
Common nonmedical treatments for dry eye include over-the-counter artificial tears and lubricating eye drops, which are suitable for infrequent issues. However, it is important to consult a doctor if symptoms persist or worsen.
The most common non-medical treatments for dry eye, such as artificial tears and lubricating eye drops are available over the counter, without a prescription. Although this is a good place to start if you have infrequent issues with dry eyes, it is important to see a doctor if symptoms persist or become worse.
What causes dry eye?
Dry eye can be caused by hormonal changes due to aging, particularly in women after menopause, as well as various factors such as autoimmune diseases, environmental conditions, prolonged screen time, contact lens use, and certain medications. Other contributing factors include thyroid disease, smoke and wind exposure, and refractive eye surgery.
Hormonal changes during aging can be a cause of dry eye. Although both men and women can get dry eye, it tends to be more common in women, especially after menopause. There are many other causes of dry eye, which including autoimmune diseases such as rheumatoid arthritis, Sjogren's syndrome, and lupus, thyroid disease, smoke exposure, wind exposure, or being in a dry climate, prolonged activities that reduce blinking such as working at a computer screen for long periods of time, or reading, wearing contact lenses for an extended period of time, refractive eye surgery such as LASIK.
Additionally, medications that can cause dry eyes include diuretics, beta-blockers, antihistamines, sleeping pills, medications for anxiety or depression, and heartburn medications.[2]
Are benzalkonium chloride-preserved eye drops harmful to eyes?
Quick answer:
Benzalkonium chloride (BAK), a common preservative used in eye drops, has been found to be toxic to the cornea and may worsen dry eye, particularly in people with glaucoma. Although some studies show no significant differences in ocular health outcomes between BAK-preserved and preservative-free eye drops, it is essential to evaluate the risks and benefits on an individual basis, especially if irritation occurs.
Preservatives are often added to eye drops to maintain sterility. One of the most common preservatives used in eyedrops is benzalkonium chloride (BAK).
Both in vitro studies and animal studies have found BAK to be toxic to the cornea and that it may exacerbate dry eyes.[9] Additionally, a cross-sectional study of adults with glaucoma found that using BAK-preserved travoprost was correlated with ocular surface disease and decreased quality of life.[10] It’s also not uncommon for people using eye drops to treat glaucoma to experience redness, burning, or irritation after using BAK-preserved eye drops.
On the other hand, a 2019 meta-analysis found that compared to preservative-free or alternative preservative eye drops, using BAK-preserved eye drops resulted in no significant differences in intraocular pressure, conjunctive hyperemia, ocular hyperemia, total ocular adverse events, or tear break-up time in people with glaucoma.[11]
In light of these mixed findings, it’s important to consider context and population when assessing the effects of BAK-preserved eye drops. Most of the research on BAK-preserved eye drops has been studied in people with glaucoma, so it may not be applicable to people with dry eye or other eye conditions.
When treating a specific condition like glaucoma or dry eye, it’s vital to weigh the risks and benefits of using BAK-preserved eye drops. If an individual is not experiencing any adverse effects, the benefits of continuing to use BAK-preserved eye drops may outweigh any potential risks.
Ultimately, if BAK-preserved eye drops cause irritation or exacerbate any symptoms, it may be wise to consider other options, such as preservative-free eye drops. However, this decision must be specific to the individual and done with the help of a qualified healthcare provider.
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References
Examine Database References
- Dry Eye Symptoms - Yun-Jung Yang, Won-Young Lee, Young-Jin Kim, Yeon-Pyo HongA Meta-Analysis of the Efficacy of Hyaluronic Acid Eye Drops for the Treatment of Dry Eye SyndromeInt J Environ Res Public Health.(2021 Mar 1)
- Dry Eye Symptoms - Larmo PS, Järvinen RL, Setälä NL, Yang B, Viitanen MH, Engblom JR, Tahvonen RL, Kallio HPOral sea buckthorn oil attenuates tear film osmolarity and symptoms in individuals with dry eyeJ Nutr.(2010 Aug)
- Dry Eye Symptoms - Matsuo T, Tsuchida Y, Morimoto NTrehalose eye drops in the treatment of dry eye syndromeOphthalmology.(2002 Nov)
- Dry Eye Symptoms - Matsuo TTrehalose versus hyaluronan or cellulose in eyedrops for the treatment of dry eyeJpn J Ophthalmol.(2004 Jul-Aug)
- Dry Eye Symptoms - Hu J, Kong L, Zhu S, Ju M, Zhang QEfficacy and safety of manuka honey for dry eye.Clin Exp Optom.(2023 Jul)