Dry eye syndrome and prolonged screen time: How strong is the connection? How to choose artificial tears? When to seek medical attention?

Modern people are spending increasingly more time in front of mobile phones, computers, and tablets every day. At the same time, discomforts such as dry eyes, heavy eyelids, red eyes, and intermittent blurred vision are becoming more and more common. Common sayings include: "Looking at screens for more than 8 hours a day increases the chance of developing severe dry eye syndrome by 14%", and "Dry eyes should be treated with preservative-free artificial tears".

Both sentences are correct in direction, but they omit the essential part that allows people to make a decision:The "14%" figure is actually the result of an online self-assessment survey, not a clinically diagnosed prevalence rate; it measures the proportional difference between two groups, not the individual probability that "each additional person has an extra risk of 14%".As for eye drops, there are indeed some considerations when choosing them—but the most overlooked reminder in the same report is actually more noteworthy than "which one to buy":Using eye drops haphazardly will not cure the underlying problem; it is best to consult an ophthalmologist for a thorough examination before using any medication.This article restores the survey results to their original significance, adding diagnostic criteria, the choice of eye drops, and warning signs that necessitate seeking medical attention.

First, let's look at that survey: what did it say, and what didn't it say?

First, let me state the source. This survey was conducted by...Orbis, together with the Hong Kong Ophthalmological Society and the Hong Kong Society for the Prevention of BlindnessThe survey was conducted online from September 4th to 18th, 2025, and collected a total of [number missing] data. 2,741 valid responsesAnd allow some respondents to pass through OSDI Ocular Surface Disease IndexThe self-assessment results were published on October 5th of the same year, World Sight Day.

Main findings of the survey

project	result
Collect valid questionnaires	2,741 copies
I was diagnosed with severe dry eye symptoms after a self-test.	About 30% (approximately 901 people)
Some of the aforementioned individuals had previously sought medical attention for dry eye problems.	Approximately 20% (or about 80%) of them have never sought medical attention.
Among them white-collar workers	684 people, accounting for 76%
Indicates prolonged use of electronic products	About 60% of people spend more than 8 hours a day looking at screens.
The difference between screen time and the proportion of severe dry eye symptoms	The group that spent more than 8 hours looking at screens had a prevalence level approximately 14 percentage points higher than the group that spent less than 2 hours looking at screens.
Among respondents aged 18 to 29, self-testing revealed severe dry eye symptoms.	About 40%

Is this survey useful? Yes, but we need to understand its context.

It has two undeniable values.First, it points out a real gap.—Among the respondents who tested positive for severe dry eye symptoms, about 80% had never sought medical attention for their dry eye problem. This percentage is enough to show that "dry eye is not a trivial matter, but it is not taken seriously" and it is a public health issue that needs to be taken seriously.

Second, it focuses attention on factors that can be changed.Screen time, ambient humidity, and contact lens wear time can indeed be adjusted. Two independent international reviews have confirmed a link between prolonged digital screen use and dry eye syndrome, and one of the repeatedly verified mechanisms is...Blinking pattern changeTherefore, the conclusion that "you should pay attention to your eye habits" is valid.

However, regarding the question of "how many people in Hong Kong suffer from dry eye syndrome," the more comprehensive international estimates do not match the answer from this self-selected sample. Estimates using the Bayesian method to integrate multiple studies from 1997 to 2021 show that the global prevalence of dry eye syndrome varies greatly depending on the diagnostic criteria used: symptomatic dry eye syndrome is approximately... 9.12%Physical characteristics 35.2%If the most stringent TFOS DEWS II diagnostic criteria are used, approximately 29.5%The same estimate also indicates that North America has the lowest prevalence of the disease, while East Asia has a higher proportion of symptomatic cases.It is clear that the reason why the figure of "30%" appears is due to the choice of which standard is used—not because Hong Kong people are particularly problematic.

II. What is dry eye syndrome? Even symptoms like "watery eyes" can indicate it.

The most common misconception about dry eye is that "dry eye is just dry eyes." This is also one of the "three major fallacies" that doctors specifically wanted to clarify when the survey was published.

According to the definition published by the international TFOS DEWS III working group in 2025,Dry eye syndrome is a multifactorial, symptomatic disease characterized by a loss of homeostasis in the tear film and/or ocular surface.Among the contributing factors are tear film instability and hyperosmolarity, ocular surface inflammation and damage, and abnormal nerve sensation. In other words, itIt is a disease, not a syndrome, and it is always accompanied by symptoms.。

The tear film has a three-layer structure, and problems with any one layer can lead to dry eye.

tear film layer	source	effect	When this layer has a problem
lipid layer	meibomian gland secretion	Preventing tear film evaporation and maintaining surface smoothness	Evaporative dry eye (most commonly caused by meibomian gland dysfunction)
Aqueous layer	Lacrimal glands and conjunctiva	Moisturizing, contains electrolytes and antibodies	Dry eye due to insufficient secretion
Mucus layer	Conjunctival goblet cells	Forms a smooth coating and reduces blinking friction	Uneven surface of the eye, increased friction

Because there are three layers,Excessive watery eyes can also be a symptom of dry eye syndrome.When tiny tears appear on the surface of the eye, the cornea and conjunctiva are irritated, triggering reflexive tearing—the eyes may appear to have sufficient tears, but the eye surface is actually dry and damaged. This is why the presence or absence of tears cannot be used as a basis for self-diagnosis.

Common symptoms of dry eye syndrome include more than just dry eyes: heavy eyelids, itching, burning sensation, foreign body sensation, redness, photophobia, and blurred vision, as well as...Tears flowed involuntarilySymptoms often worsen in the afternoon, evening, or after prolonged eye use. The relationship between eye strain and dry eye has been discussed in detail in a previous article on this site, covering general eye care; further reading is available at [link to article].How to reduce eye damage when wearing glasses>and<Prolonged use of blue light filtering products can damage the eyes.〉。

III. Wherein lies the strong link between screen time and dry eye syndrome: Reduced blinking is the core mechanism.

Two independent reviews from 2018 to 2020 explained this mechanism very clearly. When a person stares at a screen with high concentration for a long time,The frequency of blinking will decrease significantly, and the proportion of incomplete blinking (blinking without complete closure) will increase.Each complete blink is an action that redistributes the tear film evenly; if the number of blinks decreases, the lipid layer does not have time to redistribute, and the tears evaporate between two blinks.

Another frequently mentioned mechanism isScreen position and blink amplitudeWhen the screen is positioned too low or too high, the closure range of the upper and lower eyelids changes during blinking, thus reducing the efficiency of tear film redistribution. Furthermore, blue light emission from modern devices, weak airflow in front of the screen causing localized dryness, and pre-existing dry eye symptoms are all considered factors that interact with the symptoms.

Currently, there are several treatment methods that are indeed supported by research.

During a consultation, the ophthalmologist will determine the treatment plan based on the type of dry eye, as documented in both international and local clinical data. Local ophthalmology department data lists treatment options including: reducing screen time and getting sufficient rest, using moisturizing eye drops (artificial tears, gels, and ointments), avoiding dry environmental factors, applying warm compresses to the eyelids and maintaining eyelid hygiene, and using medicated eye drops as needed, as well as placing tear duct plugs.

Two of these treatments have been well supported by randomized controlled trials and are worth knowing:

IV. How to Choose Artificial Tears: Preservatives, Packaging, and Ingredients

Firstly, observational studies support the use of preservative-free artificial tears, while systematic reviews show no significant differences.

This item was included in this inspection.The most needed is a balanced statement.The part is because the two types of evidence point to different conclusions.

The side in supportA nationwide, multicenter observational study (real-world usage study) documented the conversion of dry eye patients to preservative-containing artificial tears.Preservative-free formula with hyaluronic acidThe results showed that the average OSDI score before conversion was 56.0, and after conversion it decreased to 28.2.The patient index score of TP4T improved by 97.01.Among them, 23% returned to normal. The study also pointed out that the clinical pattern of products using "mild" or "quick-drying" preservatives (such as polyquaternium salts) is the same as that of those using traditional preservatives (benzalkonium chloride).

The side that needs to be retainedA systematic review (covering 4 relevant studies screened from 2028 search results) compared preservative-free and preservative-containing artificial tears.No statistically significant differences were found in OSDI symptom scores, Schirmer's tear secretion, tear film breakup time, burning sensation, foreign body sensation, and photophobia.The authors concluded that "there is no evidence that preservative-free artificial tears are superior to those containing preservatives."

The two are not truly contradictory. Observational studies record...Changes in patients after switchingA systematic review comparesComparison results between different formulationsThe former lacked a control group, therefore the placebo effect and natural fluctuations in the condition could not be ruled out. A more conservative understanding is:For people who already need to use eye drops long-term, switching to a preservative-free formula is a low-risk approach with empirical support; however, it is inappropriate to claim that it is clearly effective for everyone.

As for why preservatives themselves warrant caution, there are mechanistic studies at the animal and cellular levels: benzalkonium chloride causes dose-related damage to the corneal and limbal epithelium, including punctate staining, epithelial cell disorder, and a reduction in goblet cells; in cultured cells, concentrations as low as 0.00011 TP4T reduce colony-forming ability. This is the mechanistic basis for understanding why long-term use of eye drops containing preservatives should be approached with caution.However, it should be noted that these are laboratory and mouse models, and cannot be directly equated with the results after human eye use.Another randomized controlled trial involving 460 participants over 90 days showed that products containing carboxymethyl cellulose and hyaluronic acid...Preservative-freeCompared to the carboxymethyl cellulose-only formulation, the two formulations showed comparable efficacy (OSDI scores decreased by 16.9 and 16.0 points, respectively) and good safety profiles.

V. Routine tasks: Which are supported by actual measurements, and which require discounting?

The 20-20-20 rule: supported by research, but its effectiveness needs to be maintained over time.

The rule "rest your eyes for 20 seconds every 20 minutes of screen time" is most often cited. A randomized study of 29 computer users with symptoms of digital eye strain tested this method using software reminders for two weeks, and the results showed:Reduced screen time and increased breaks improved symptoms of dry eyes and digital eye strain.(p ≤ 0.045).

However, the same study also provides two limitations that must be known:The improvement did not last after a week of stopping the reminders.Furthermore, all objective indicators of the tear film and ocular surface (tear river height, conjunctival hyperemia, lipid layer thickness, non-invasive tear film breakup time, corneal and conjunctival staining, etc.)No significant changes were observed during the testing period.In other words, the 20-20-20 rule applies to...Relieve discomfortThere is experimental evidence to support this, but no evidence of substantial changes to the ocular surface—it is a habit worth maintaining long-term, not a treatment.

Desktop humidifier: Supported by a small randomized trial, worth a try.

Dry office environments are a common contributing factor, and the effectiveness of desktop USB humidifiers has previously lacked evidence. A randomized crossover trial of 44 computer users provided the first positive answer: under conditions of a relative increase in humidity of approximately 5.41 TP4T,The median tear film breakup time increased by 4.0 seconds in non-invasive procedures.(p < 0.001), andThe proportions feel more comfortable than what I'm seeing now, increasing from 5% to 36%.(p < 0.001). No difference was observed in lipid layer gradation and tear river height.

The study authors concluded with considerable restraint: even with a small increase in humidity, humidifiers showed potential to improve dry eyes. This was a small-scale experiment, but it was well-directed, low-cost, and a reasonable first-line solution for people who spend long hours in air-conditioned offices.

Blinking and Indoor Humidity: Low Cost, Can Be Done Immediately

Since the core mechanism is to reduce blinking,Intentional blinking and avoiding prolonged exposure to dry airThese become the two lowest-cost steps. Daily eye care tips can be found on the site.Early signs of aging in the eyes and their care〉。

Blue light filters: No actual effect on dry eye symptoms observed in testing.

This point is often misunderstood. Regarding the claim that "blue light damages the eyes," another article on this site has provided a detailed verification (see the extended reading link above). As for dry eye, a randomized crossover study of 26 participants had them perform a 120-minute tablet reading task with three different lenses (blue light blocking, anti-reflective coating, and no coating). The results were:There were no significant differences among the three types of lenses in terms of dry eye symptoms (DEQ-5, OSDI) and signs of dry eye (tear window height, non-invasive and fluorescein tear film breakup time).The authors' conclusion is clear: blue light blocking lenses did not alleviate dry eye symptoms and signs during 120 minutes of digital activity.

in other words:There's no need to buy blue light blocking glasses specifically for dry eye syndrome.

Contact lens wearing time: This point was also mentioned in another old article on this site.

Related reports cite doctors' advice to wear contact lenses for no more than 10 hours a day and to allow the eyes to rest. (Previous post on this site)My eyes are watering for no reason as the cold wind blows; I'm worried about a dry eye attack.The book provides a relatively complete explanation of the causes, classifications, and treatments of dry eye syndrome, and can be consulted accordingly.

VI. Omega-3 and Dry Eye Syndrome: Symptoms may improve, but this does not mean the condition is cured.

Dry eye syndrome is a highly sensitive topic, and it's particularly easy to overstep boundaries when discussing supplements. Here, we present the current state of research.

Newer systematic reviews and meta-analyses have yielded more positive results.A 2023 review covering 19 randomized controlled trials and 4,246 patients with dry eye reported that the group supplemented with Omega-3 showed superior results compared to the placebo group in symptom score (Hedges' g = −1.047, p < 0.001), tear film breakup time, Schirmer test, corneal fluorescein staining, and osmolarity.

However, another concurrent review reached a much more conservative conclusion.A 2023 updated systematic review and meta-analysis in *Acta Ophthalmologica* included 8 parallel randomized controlled trials with 1,107 participants. The results showed that improvements in OSDI scores from baseline to final assessment did indeed occur, but...There was no significant improvement in corneal staining, tear film breakup time, or Schirmer score.Moreover, the review clearly points outNone of the included studies achieved a low risk of bias.The statistical heterogeneity of the four results is quite high.

How should we understand this gap?The generally accepted interpretation is that Omega-3 may help with dry eye symptoms (discomfort experienced by patients), but its effect on objective indicators of the tear film and ocular surface has not been established.However, the quality of existing trials still has room for improvement. If supplementation is considered, diet should be prioritized, and adjustments should be made under the guidance of a doctor—those with dry eye syndrome who also have other health conditions or are currently taking medication should especially avoid self-supplementation.

Regarding the benefits of Omega-3 for general eye health, there is already a dedicated article on this site, which can be found here:Omega-3 fatty acids and eye health>and<A comparison of the effects of lutein and anthocyanins on eye health.〉。

VII. When is it necessary to seek medical attention?

During the consultation, the doctor will make a diagnosis according to international standards: first, use screening questionnaires such as DEQ-5 or OSDI to confirm the possible presence of dry eye syndrome, then conduct (as non-invasive as possible) tests such as tear film breakup time, tear osmolarity, and fluorescein/lixamine green staining, and then classify the condition according to the loss of tear film lipids, aqueous and mucus/glycocalyx, as well as eyelid and ocular surface abnormalities.The classification result directly determines which treatment to use.This is why "try buying a bottle of artificial tears first" is often not enough—different types can have completely opposite treatment approaches.

When should prescription or procedural treatment be considered?

For moderate to severe dry eye that does not respond adequately to lubricating eye drops, doctors may consider prescription eye drops containing immunosuppressive or anti-inflammatory ingredients. For example, a multicenter randomized controlled trial (ESSENCE study) evaluated the efficacy and safety of anhydrous 0.1% cyclosporine solution for moderate to severe dry eye. These medications require a doctor's prescription and monitoring and are not available for self-purchase.

For meibomian gland dysfunction, there are thermal pulsation therapy devices (common brand LipiFlow).This must be stated in a balanced manner.The authors of the Cochrane systematic review (updated in 2024, including 13 randomized controlled trials and 1,155 participants) concluded that—regarding the signs and symptoms of dry eye,LipiFlow's performance is similar to other commonly used dry eye treatments.The best available evidence was rated as having a high risk of bias, low or very low certainty, and requires more comprehensive blinding and standardized testing studies to draw definitive conclusions. The review also did not report any treatment-related adverse events that endangered vision.

in other words:Heat pulsation therapy can be considered as an option, but it is not a "better choice," and there is currently insufficient evidence to support its superiority over other treatments such as heat therapy.

8. Other high-risk factors that were overlooked

The original report focused on screen time, but there are many more risk factors for dry eye than just screen use. The following factors are often overlooked:

factor	illustrate
Age and gender	Global epidemiological estimates show that the prevalence of dry eye syndrome increases roughly linearly with age; the prevalence of symptomatic dry eye is approximately 9.51 TP4T in women and approximately 6.81 TP4T in men. Local reports also indicate that women are more likely to experience severe dry eye symptoms.
Low humidity and air-conditioned environment	Prolonged exposure to air-conditioned or heated office environments can accelerate tear evaporation; this is the background for the desktop humidifier experiment.
Long-term contact lens wear	It can increase tear film instability and tear evaporation. Related reports suggest wearing it for no more than 10 hours a day and scheduling rest days.
Systemic autoimmune diseases	Conditions such as rheumatoid arthritis, lupus erythematosus, and Sjögren's syndrome can all affect tear secretion.
After eye surgery or laser vision correction	Postoperative changes in the tear film and ocular surface condition require special attention.
Long-term use of certain medications	Related reports mention that antihypertensive drugs and antidepressants may affect tear secretion.
Vitamin A deficiency	One of the typical symptoms of long-term severe vitamin A deficiency is dry eyes and night blindness; this issue has been addressed in other sections of this site.

IX. Frequently Asked Questions (FAQ)

Can dry eye lead to blindness?

Dry eye syndrome can indeed lead to vision impairment. This occurs because long-term dryness and inflammation of the ocular surface cause damage to the corneal epithelium, which can develop into corneal ulcers and perforations in severe cases, ultimately affecting vision. However, this is..."Serious and untreated"This is not a necessary outcome of typical dry eye syndrome. The vast majority of patients can control their symptoms with early identification, correct classification, and appropriate treatment. The report mentioning that "severe cases can lead to blindness" emphasizes this crucial point and is a key reason for urging against neglecting the condition for extended periods.

My eyes often water. Does that mean my eyes are moist enough and I don't have dry eye syndrome?

Not necessarily; this is one of the most common misconceptions. When the surface of the eye has developed tiny abrasions due to prolonged dryness, irritation to the cornea and conjunctiva can trigger [a reaction].Reflexive tearingThis leads to the situation where "your eyes are already wet, but tears keep flowing." Diagnosing dry eye relies on the overall condition and examination, not just looking at whether there are tears.

If there's no time for an examination, can I use lubricating eye drops to tide me over?

Lubricating artificial tears are available at pharmacies and are reasonable for short-term use to relieve discomfort. However, please note two points: First, if you need to use them more than 6 times a day, it means your eye condition is beyond your self-care range; second, if symptoms do not improve after two weeks of use, or if your eyes become red, sensitive to light, or your vision becomes blurred, you should not continue to treat them yourself but seek medical attention. If you also wear contact lenses or have had eye surgery, you should consult a doctor first.

How should you choose between artificial tears with and without preservatives?

It can be judged from three dimensions.First, the frequency of useFor those who need to use it multiple times a day or for a long period of time, it is advisable to choose a single-use pack without preservatives.Second, packagingOnce opened, each single-use pack should be used within the specified time as instructed and should not be kept for later use.Thirdly, the ingredientsCommon lubricant bases include hyaluronic acid, carboxymethyl cellulose, polyvinyl alcohol, and carbomer, which can be selected according to personal comfort. It should be noted that while preservative-free formulations are supported by real-world observational studies, systematic reviews have not found statistically significant differences between them and preservative-containing formulations; therefore, they should not be considered definitively more effective for everyone.

Can I still wear contact lenses if I have dry eye syndrome?

You should consult a doctor for evaluation first. Dry eye syndrome increases tear film instability, and wearing contact lenses further increases ocular surface friction and evaporation, exacerbating the condition. Related reports recommend wearing contact lenses for no more than 10 hours a day and scheduling rest days. However, if you have been diagnosed with dry eye syndrome, the duration of contact lens wear and whether you can continue wearing them should be determined by your doctor based on your tear film condition; you should not make your own judgment.

Are blue light blocking glasses useful?

Regarding dry eye, current randomized controlled trials have yielded negative results: a randomized crossover study of 26 participants involved reading for 120 minutes with each of three lenses—blue light blocking, anti-reflective coating, and no coating—and no significant differences were found in dry eye symptoms and signs among the three groups. The conclusion clearly indicates that blue light blocking lenses do not alleviate dry eye. Therefore...There's no need to buy blue light blocking glasses specifically for dry eye syndrome.To learn more about the overall verification process for blue light blocking products, please read the following article on the website:Prolonged use of blue light filtering products can damage the eyes.〉。

Will I definitely get dry eye syndrome if I look at a screen for 8 hours a day?

No. Screen time is indeed associated with dry eye symptoms, but association does not equate to a definite link. Related reviews indicate that the strongest evidence linking prolonged screen time to dry eye is that it...Change blinking dynamics(Decreased blinking frequency and increased incomplete blinking) accelerates tear evaporation. The same review also points out that pre-existing dry eye syndrome may, in turn, become a triggering or aggravating factor. Therefore, screen time is a variable that needs to be managed, but factors such as dry air, low humidity environments, contact lens wear, and systemic diseases that exist concurrently are equally important.

Are eye drops and artificial tears the same thing?

These are not the same category. Artificial tears are lubricants, primarily used to replenish moisture, reduce friction, and soothe symptoms; eye drops are a broader term, encompassing prescription preparations with therapeutic effects such as anti-inflammation, immunosuppression, antibiotics, intraocular pressure reduction, and mydriasis. Therefore, the approach of "buying eye drops for dry eyes" is incorrect—which type to use depends on the type and severity of dry eye syndrome, and the type must be determined through examination.

Can the OSDI self-test be used as a diagnostic tool?

No. The OSDI is an internationally used clinical screening questionnaire intended to indicate that "further testing may be needed," not to establish a diagnosis. The international TFOS DEWS III diagnostic criteria clearly state that a positive screening questionnaire indicates...It also needs to be combined with non-invasive tear film breakup time (<10 seconds), or turbidity osmotic pressure (≥308 mOsm/L in either eye, or difference between the two eyes >8 mOsm/L), or corneal fluorescein staining >5 points and conjunctival lixamine green staining >9 points, etc.Only after these steps can a diagnosis of dry eye be established. This is why online self-tests are suitable for "deciding whether or not to see a doctor," rather than for determining whether you have a disease.

Source of information

Official and institutional data

• Ophthalmology Department, Hong Kong Sanatorium & Hospital: Dry Eye Syndrome - Diagnosis and Treatment—Definition, symptoms, diagnostic tests, and treatment options for dry eye syndrome
• Hospital Authority Health Information NetworkEye Health and Medical Information
• Centre for Health Protection Health Page

Medical Research (PubMed)

• TFOS DEWS III: Diagnostic Methodology（Am J Ophthalmol (2025) — Latest definition and diagnostic criteria for dry eye syndrome (OSDI-6 score ≥4)
• TFOS DEWS II Diagnostic Methodology report（Ocul Surf (2017) — Division of Labor in Screening and Diagnosis Processes
• The global prevalence of dry eye disease: A Bayesian view（ Ophthalmic Physiol Opt (2021) — Differences in global prevalence estimates and diagnostic criteria
• The Relationship Between Dry Eye Disease and Digital Screen Use（Clin Ophthalmol (2021) — A review of the association between screen use and dry eye syndrome
• Digital Screen Use and Dry Eye: A Review（Asia Pac J Ophthalmol (2020) — A review of the pathogenic mechanisms of abnormal blinking, etc.
• Rasch analysis of the Ocular Surface Disease Index (OSDI)（Invest Ophthalmol Vis Sci (2011) — Structure and Limitations of the OSDI Scale
• The effects of breaks on digital eye strain, dry eye and binocular vision: Testing the 20-20-20 rule（Cont Lens Anterior Eye (2023) — A Stochastic Study of the 20-20-20 Rule
• Randomized Trial of Desktop Humidifier for Dry Eye Relief in Computer Users（Optom Vis Sci (2017) — Randomized Crossover Trial of Desktop Humidifiers
• Effect of blue-filtering lens spectacles on signs and symptoms of dry eye during exposure to a digital screen（Ophthalmic Physiol Opt (2025) — A randomized study of the effects of blue light blocking lenses on dry eye.
• Real-life results of switching from preserved to preservative-free artificial tears containing hyaluronate（Clin Ophthalmol (2018) — An observational study on switching to preservative-free artificial tears.
• Effectiveness of using preservative-free artificial tears versus preserved lubricants: a systematic review（Arq Bras Oftalmol (2019) — A systematic review of two types of artificial tears
• Safety and Efficacy of a Preservative-Free Artificial Tear Containing Carboxymethylcellulose and Hyaluronic Acid（Clin Ophthalmol (2020) — A randomized controlled trial involving 460 people over 90 days.
• Dose-dependent benzalkonium chloride toxicity imparts ocular surface epithelial changes with features of dry eye disease（Ocul Surf (2020) — Dose-related ocular surface damage of benzalkonium chloride
• Efficacy of Omega-3 Intake in Managing Dry Eye Disease（J Clin Med (2023) — A review of 19 RCTs and 4,246 participants
• Omega-3 fatty acids in the management of dry eye disease—An updated systematic review and meta-analysis（Acta Ophthalmol (2023) — 8 RCTs, 1,107 participants; symptoms improved but objective indicators did not.
• Efficacy and Safety of a Water-Free Topical Cyclosporine, 0.1%, Solution for the Treatment of Moderate to Severe Dry Eye Disease (ESSENCE)（JAMA Ophthalmol 2023)
• LipiFlow for the treatment of dry eye disease（Cochrane Database Syst Rev (2024) — 13 RCTs, 1,155 participants; similar to other treatments.

Source of investigation

• Orbis, in collaboration with the Hong Kong Ophthalmological Society and the Hong Kong Society for the Prevention of Blindness, conducted an online survey from September 4 to 18, 2025, receiving 2,741 valid responses. The results will be released on October 5, 2025, World Sight Day. The survey collected data using a self-selected online questionnaire and the OSDI self-assessment.Screening rather than clinical diagnosisThe limitations have been explained in the main text of this article.