What are the causes of dry eye? Common culprits are advanced years, prolonged screen time, conditioned air, contact lenses, and certain medications like antihistamines or antidepressants. Opticians play a vital role in diagnosing and treating dry eyes, helping you find relief through tailored care and advice. This guide explores common causes, symptoms, and effective strategies recommended by opticians to manage dry eyes properly.
Understanding Dry Eye
Dry eye occurs when the eyes don’t produce enough natural tears, or the tears disperse and evaporate too quickly. The result is discomfort, intermittent blurred vision and tired eyes. It’s known as dry eye syndrome or dry eye disease, and in medical terms, keratoconjunctivitis sicca. It strikes at any age, although risk increases with advancing age.
Tears are not simply water. The tear film has three layers that sit on the surface of the eye: a top layer of fatty oils from the meibomian glands in the eyelids that slows evaporation, a middle layer of aqueous fluid that hydrates and feeds the cornea, and a bottom layer of mucus that helps the tears spread evenly. When any layer is thin or of lower quality, the film breaks up prematurely. That’s when eyes sting, burn, or feel scratchy, and you might spot stringy mucus on the lashes or in the corners. Ironically, eyes can water even more because the dry surface sends a distress signal, and those tears can be watery and do not calm.
What you experience differs. Some report a gritty or sandy feeling, light sensitivity or heavy eyelids. Long spells of reading, night driving or staring at a screen can aggravate symptoms. You may experience dry eye in places such as on board a flight, in air-conditioned and heated rooms, or while cycling with the wind in your face. Contact lens wear can exacerbate it, particularly later in the day.
It occurs due to the amount or quality of tears, or a combination of the two. Ageing reduces tear production. Meibomian gland dysfunction is common and starves the tear film of oils, so tears evaporate quickly. Certain medicines can dry the eyes, such as antihistamines, some antidepressants, acne medication and diuretics. Disease processes including rheumatoid arthritis and Sjögren’s syndrome increase risk because they can damage the lacrimal glands or eyelids themselves. Long periods of time in dry air, dust, smoke and even high-altitude climates can push a mild case into a bad day.
Little daily steps do. Wash your eyelids daily using warm compresses or gentle lid wipes to keep the oil glands clear. Blink more often when on screens and employ the 20-20-20 rule to give your eyes a break. Have breaks from the TV and position screens at eye level to decrease glare. Supplement omega-3 and omega-6 fats via oily fish, nuts and seeds as these could help maintain the tear film. If you wear contacts, match lens type and solution to dry eye and allow your eyes lens-free hours.
What Causes Dry Eyes?
What causes dry eyes? Weather, lifestyle and general health all contribute. Medications, wearing contact lenses and previous eye surgery are risk factors.
| Common cause | What it does | Example triggers |
| Reduced tear production | Fewer baseline tears | Ageing, Sjögren’s, rheumatoid arthritis |
| Increased evaporation | Tears break up quickly | Wind, AC, screens, meibomian gland blockage |
| Poor tear quality | Unstable tear film layers | Blepharitis, eyelid margin issues |
1. Tear Production
Tears originate in the lacrimal glands. When output decreases, the surface desiccates, nerves fire, and the eye feels grainy or sore. Ageing is a key culprit. Gland function slumps over the years, so most people experience symptoms from mid-life. Autoimmune disease is another path. Sjögren’s syndrome, rheumatoid arthritis, lupus, scleroderma, sarcoidosis, thyroid disorders, and graft-versus-host disease can all blunt secretion. Vitamin A deficiency, while less prevalent in high-income countries, attacks the eye surface.
Some medications reduce natural tear output. Antihistamines, decongestants, diuretics, antihypertensives, antidepressants, birth control, hormone replacement therapy, isotretinoin and Parkinson’s medicines are common offenders.
2. Tear Quality
Tear film has three layers: oil, water, and mucus. When these fall out of step, tears break fast and sections of the cornea remain unshielded. Meibomian gland dysfunction (MGD) is at the heart of it. These tiny oil glands along the lid rim get blocked or deplete, creating a fragile lipid layer and rapid tear break-up. The result is a burning sensation that intensifies throughout the day.
Chronic blepharitis and lid margin issues complicate the picture. Debris on lashes and biofilm disrupt the oil composition, and abnormal lids lead to poor spread with every blink.
3. Environmental Factors
Wind, dust, dry air and smoke evaporate moisture from the eye. Indoor air conditioning, central heating and low humidity speed up evaporation too.
Restore moisture with a room humidifier. Wear wraparound safety glasses or goggles in harsh environments. Outside, sunglasses shield wind and UV and help to lock tears in place.
4. Lifestyle Choices
Long screen time slows your blinks. Less blinking leads to faster tear loss and sorer, more tired eyes. Smoking and even second-hand smoke irritate lids and damage glands.
Stick to the 20-20-20 rule and consciously blink. You can keep lids clean and remove eye make-up each evening to reduce flare-ups. Contact lenses increase risk too, especially if worn without care or for long periods.
5. Systemic Health
Autoimmune disease, for example, lupus and thyroid eye disease, frequently triggers chronic dryness. Hormonal changes in menopause diminish quantity and oil quality. Diabetes affects nerves and surfaces, while allergic conjunctivitis inflames tissue and destabilises the film. Corneal nerves can lose feeling after wearing contact lenses or laser surgery, which dampens reflex tearing and exacerbates dryness.
How Is It Diagnosed?
Diagnosis begins with a comprehensive eye exam and detailed history because symptoms often overlap and causes vary. The hope is to chart what is going on on the eye’s surface, how stable the tear film is, and which layer—oil, water, or mucus—is breaking down.
Initial Consultation
Clinicians question specific symptoms of dryness, burning, blur that clears with blink, light sensitivity and gritty feel. They look at when symptoms start, how long they last and what aggravates them, such as air conditioning, wind, smoke or prolonged screen use.
They grade severity and frequency to identify flares versus continuous pain. This facilitates distinguishing mild evaporative stress from more severe aqueous loss and guides what to test for first.
History includes previous eye disease, autoimmune disease, allergies, and medications that dry the eye, including antihistamines, isotretinoin, antidepressants, or diuretics. They share which drops they use, how often, and whether gels or ointments help at night.
Work roles matter. Dusty sites, flow-hood labs, or long-haul flights put you at higher risk. Basic safety measures such as wraparound eyewear, humidifiers, and scheduled breaks can be included in future recommendations.
Clinical Tests
Standard tests check tear volume and stability. Schirmer’s test uses a paper strip under the lower lid to measure tear production over minutes. The phenol red thread test places a pH-sensitive thread over the lower eyelid for 15 seconds. Less than 15 mm of colour change points to low aqueous volume.
Fluorescein and lissamine green stains highlight punctate injury on the cornea and conjunctiva, indicating where the tear film breaks down and cells are stressed. Tear film break-up time (TBUT) indicates how quickly the film breaks down after a blink.
TearLab measures osmolarity (saltiness). InflammaDry detects elevated MMP-9, a marker of surface inflammation. Tear samples can be analysed for low lactoferrin, adding further information on gland output and patterns of inflammation.
| Test | What it measures | Key clue |
| Schirmer’s | Aqueous tear production | Low mm suggests deficiency |
| Phenol red thread | Quick tear volume | <15 mm in 15 s suggests dry eye |
| TBUT | Tear stability | Fast break-up implies evaporation |
| Fluorescein/Lissamine | Surface damage | Staining maps cell stress |
| TearLab osmolarity | Tear saltiness | High/uneven = instability |
| InflammaDry | MMP‑9 level | Positive = inflammation |
Advanced Imaging
Non-invasive techniques add depth to the picture. Meibography, including devices like LipiScan, provides high-resolution images of meibomian glands, displaying dropout, truncation, or atrophy that drives lipid layer failure and rapid evaporation. Videokeratography tracks corneal shape and dynamic tear spread, while tear meniscus height measures volume at the lid margin without touching the eye.
Ocular Surface Analysis Suites integrate these views with non-invasive TBUT, lipid layer thickness and blink quality. Subtle variations in conjunctival condition and tear film patterning reveal themselves, which aid in selecting the appropriate protocol.
Imaging links findings to action: heat and lid massage for gland loss, anti-inflammatory drops when MMP‑9 is raised, or punctal plugs when volume is low.
How Is It Managed?
Management aims at relief, ocular surface protection, and the underlying cause of the dryness. Care typically transitions from basic home measures to medical therapy and then to procedures if symptoms continue.
- Preservative-free artificial tears, gels, and ointments
- Eyelid hygiene and warm compresses or eye masks
- Environmental changes: humidifiers, screen breaks, airflow control
- Prescription drops: cyclosporine, short courses of corticosteroids
- Treatment of allergies or autoimmune disease
- Punctal plugs to reduce tear drainage
- Special lenses, minor interventions and surgical reconstruction for significant cases.
Home Care
Your daily eyelid hygiene care is the cornerstone. How to manage it? Each day, wash the lids with a warm flannel. Then use a warm compress or reusable eye mask for 5 to 10 minutes to soften blocked meibomian glands. A soft lid massage after experiencing heat can enhance oil flow, slowing tear evaporation and stabilising the tear film.
Preservative-free artificial tears in the day but thicker gels or ointments at night, particularly if you wake with gritty, sore eyes. If allergies are involved, antihistamine or mast-cell stabiliser drops might be beneficial. Some oral antihistamines can increase dryness, so discuss options with a clinician.
Make your space. Add a humidifier to boost indoor moisture. Forty to fifty percent relative humidity is optimal and avoid fans or air conditioning blowing in your face. Steer clear of smoky, dusty rooms, curb alcohol and give up smoking if you can. Smoke irritates the surface.
Blink intentionally. Stick to the 20-20-20 rule, take scheduled breaks and position your screen just below eye level so the eyelids cover more of the eye. Short, frequent breaks on long drives or in front of the TV help.
Medical Treatments
Topical anti-inflammatories can soothe the skin surface. Cyclosporine drops, such as Restasis, modulate immune-mediated inflammation over weeks to months. Short, tapering courses of corticosteroid drops can calm flares and are employed under supervision to prevent pressure surges.
Drive Promise. Control allergic conjunctivitis, blepharitis, rosacea or autoimmune disease with appropriate medications, such as antihistamine drops, lid-directed antibiotics or systemic therapy overseen by a specialist.
Punctal plugs, often made of soft silicone, obstruct tear drainage at the puncta to hold tears on the eye for longer. They are an instant fit in clinic, too, whether short-term or semi-permanent.
For severe or resistant disease, there are options such as autologous serum eyedrops made from your own blood and newer therapies in specialist centres.
Surgical Options
Minor procedures include punctal plug insertion or thermal cautery of the drainage openings to restore moisture when plugs fail or drop out.
Bandage contact lenses and scleral lenses vault the cornea, contain a reservoir of fluid and cover the surface, relieving pain and facilitating healing.
Correcting eyelid issues, such as entropion, ectropion or defective blink, enhances tear film distribution and reduces evaporation. In severe corneal degeneration, surgeons may employ conjunctival grafts, amniotic membrane or keratoplasty when scarring or thinning endangers vision.
The Digital Age Dilemma
Dry eye is increasing with screen-bingeing lives, propelled by changed blinking and accelerated tear depletion. Screen time is becoming a major risk factor for dry eye syndrome (DES), with prevalence among screen workers having been reported as high as 9.5% to 87.5%. During Covid-19 lockdowns, 64% increased their screen time, and 95.8% experienced at least one DES sign. Smartphones are the most used device, with 61.7% of patients reporting this, and over half of patients report over 6 hours of screen time a day. Kids don’t escape either; 9–10-year-olds spend an average of 3.8 hours a day on their screens. Halving average daily screen time to 4 hours or less mitigates the risk.
Screen Strain
Staring at a screen slows blinking, sometimes by half, and blinks become shallow. This leaves the tear film thin and patchy, so it breaks up quickly. The exposed cornea dries much quicker, and the cycle of irritation, reflex tearing and further evaporation begins.
Reduce screen brightness to the level of room light and contrast to a comfortable maximum. Harsh glare exhausts the eyes and induces tiredness. A matte screen filter aids in bright rooms or by windows.
Position screens just below eye level so the eyelids obscure more of the eye. Less surface area in the air leads to slower evaporation, which is basic physics but it works.
For extended sessions, have preservative-free artificial tears ready and use them before you start to feel discomfort. They stabilise the tear film and make things more tolerable throughout the day.
Blinking Patterns
Full, regular winks distribute the oily and watery layers uniformly, as if polishing in a coat of varnish. When blinks remain unmade, it is the lower cornea that dries first and stings.
Train a fuller blink: every 20 minutes, close slowly, pause for a count of two, then open. Do it five times. It seems strange at first but it grows a better habit.
Follow cues. Put that phone or app reminder in, or match blinks with habitual tasks – new email, a message ping or the conclusion of a paragraph. Monitor your pace for a week to discover when you tend to fall down most.
Workspace Ergonomics
Prevent vents, fans and heaters from blowing air directly at your face. Moving air accelerates evaporation. If air flow cannot be adjusted, employ a desk shield or alter seat position.
Minimise eye strain with anti-glare screens and neutral, indirect light. Stay away from bright backlight from windows behind the monitor and diffuse overhead glare with diffusers.
Mind distance and angle: 50 to 70 cm from eyes, with the top of the screen a little below eye level. This aids hoods to mask more of the eye and maintains neutral posture. Employers can assist with standards, training, and availability of basic eyewear, humidifiers, shades, and lubricants. Awareness, ergonomic training, and a comfortable set-up stave off DES and safeguard staff.
Beyond the Obvious Causes
Dry eye isn’t just about screens, age or wind. It frequently lurches at the periphery of larger body systems, routines, and decisions. Consider it in layers, as the tear film itself is – oils, water and mucus – because there can be ruckus a long way from the eye and still unsettle all three.
The Gut-Eye Axis
Gut health can predispose to the low-grade inflammation that eventually reaches the ocular surface. When the microbiome skews after frequent antibiotics, ultra-processed diets, or chronic stress, immune signals may shift and meibomian glands at the lid edge can clog more readily. That oil layer depletes or compromises and tears split quickly.
Bad digestion robs the eyes of essential nutrients. Vitamin A nourishes the cornea and mucus layer. Omega-3s influence meibum quality and decrease surface inflammation. Deficits present as burning, blurring and that gritty sensation that never seems to align with your hours of screen time.
Log food, bowel changes and reflux alongside dry eye flares for four to six weeks. Pay attention to triggers like alcohol, spicy meals or sweets. Share the log with your clinician.
As an adjunct to usual treatment, warm compresses, lid hygiene, and lubricants, think probiotic foods such as live yoghurt, kefir, and kimchi, along with anti-inflammatory diets heavy in fish, flaxseed, whole grains, and greens. This does not supplant treatment for autoimmune conditions, diabetes, and thyroid problems, any of which can compromise the quality and quantity of tears.
Hormonal Fluctuations
Hormones direct the lacrimal and meibomian glands. Falling oestrogen and androgen changes during menopause and perimenopause thin the oil layer and alter tear proteins. During pregnancy, changes to fluid and immunity can render the skin dry but reactive. Thyroid problems, prevalent globally, can alter blink and lid position, destabilising tears.
Women face higher risk because sex hormones act on tear glands and eyelid margins. Add age and the aqueous layer drops further, making symptoms more stubborn after 50 years.
Hormone replacement therapy might alleviate some symptoms but aggravate dryness in others, depending on dosage and type. The same applies to birth control. Go over medicines that dry eyes, including antihistamines, decongestants, antidepressants, acne drugs, blood pressure tablets, and Parkinson’s drugs, and consider swaps if possible.
If you are pregnant, postpartum, perimenopausal, or altering thyroid medication, monitor dryness weekly and schedule sooner checks if lenses or laser surgery have dulled corneal nerves.
Cosmetic Procedures
Eyelid surgery, lash lifts and extensions can disturb lid margins, change blink, and press on meibomian gland openings. Pesky peels or potent acid facials too close to peepers can irritate fragile skin and affect the oil that helps tears stay stable.
Some mascaras, glues and removers irritate the margin and provoke blepharitis. If allowed to go rogue, glands become clogged. The fatty layer thins and the watery layer evaporates quickly, particularly in dry rooms with heating or air conditioning.
She is gentle oil-free removers. Dab along the lash line with warm compresses, then a gentle lid wipe. Stay away from scented products, glitter and waterproof formulas if you experience stinging or morning crust.
Pre-cosmetic eye work may involve dry eye risk, healing time, and gland health. If you already have chronic dryness, meibomian gland dysfunction, or an autoimmune disease such as Sjögren’s syndrome, visit an eye care specialist first.