What Causes Dry Eyes? Common Causes & Treatments

Age-related risk: Over 50 ·
Screen time risk: Prolonged computer use ·
Contact lens risk: Wearing contact lenses ·
Environmental risk: Air-conditioned or dry climates

Four key facts shape how doctors think about dry eye:

What is the most common cause of dry eyes?

The most common culprit is a breakdown in the tear film — the thin layer of moisture that keeps your eyes smooth and comfortable. This can happen in two ways: your eyes don’t produce enough tears (aqueous-deficient dry eye), or your tears evaporate too quickly (evaporative dry eye). According to Mayo Clinic (leading US medical center), these two mechanisms underlie most cases.

Tear film dysfunction explained

• The tear film has three layers: oil, water, and mucus. If any layer is off, stability suffers.
• Evaporative dry eye — the more common type — often stems from blocked oil glands (meibomian gland dysfunction).
• Aqueous-deficient dry eye results from lacrimal gland issues, often age- or disease-related.

Aqueous-deficient vs. evaporative dry eye

The National Eye Institute (US government research body) explains that aqueous-deficient dry eye is less common but more directly linked to systemic conditions like Sjögren’s syndrome. Evaporative dry eye, by contrast, is driven by environmental factors and lid disease.

Age as a primary factor

Age is one of the strongest predictors. Mayo Clinic (leading US medical center) notes that people older than 50 are far more likely to experience dry eyes. Tear production naturally declines with age, and meibomian glands become less efficient.

Bottom line: For patients over 50, age-related tear film changes are the primary driver. For younger adults, screen habits and contact lens wear often take the lead.

Which deficiency can cause dry eyes?

Nutrition plays a bigger role than many realize. Several vitamin and nutrient deficiencies have been linked to dry eye symptoms, and some of the evidence is surprisingly strong.

Vitamin A deficiency

Vitamin A is essential for the health of the ocular surface. Mayo Clinic (leading US medical center) lists a diet low in vitamin A as a confirmed risk factor for dry eyes. Severe deficiency can also cause night blindness and even corneal damage.

Vitamin D deficiency

The link between vitamin D and dry eye has been studied extensively. A PMC review (peer-reviewed medical literature) found that lower serum vitamin D levels correlate with lower tear break-up time, lower Schirmer test values, and tear hyperosmolarity. The same review reports that vitamin D supplementation may improve ocular surface conditions.

Omega-3 fatty acids deficiency

Omega-3s help regulate meibomian gland function. Mayo Clinic (leading US medical center) lists low omega-3 intake as a risk factor, and many eye specialists recommend increasing dietary sources like fish or flaxseed.

B12 deficiency and eye health

The National Eye Institute (US government research body) notes that B12 deficiency can cause dry eye symptoms, though the mechanism is less clear. Some studies suggest B12 supplementation helps improve tear quality.

Bottom line: Vitamin D and omega-3 deficiencies are the most actionable nutritional factors. A simple blood test can identify gaps, and supplementation often provides measurable symptom relief.

How do I stop my dry eyes?

Treatment usually starts with the simplest changes and escalates only if needed. The goal is to restore a stable tear film.

1. Use artificial tears as needed. Mayo Clinic (treatment guidance) recommends preservative-free drops if you need them more than four times a day.
2. Apply warm compresses daily for 5–10 minutes to unclog oil glands.
3. Take regular screen breaks and blink more to reduce tear evaporation.
4. Use a humidifier in air-conditioned or heated rooms to maintain moisture.
5. Consider prescription drops or omega-3 supplements if steps 1-4 don’t provide sufficient relief.

Lifestyle changes

• Take regular screen breaks — the Mayo Clinic emphasizes that blinking less during computer work increases tear evaporation.
• Use a humidifier in dry or air-conditioned rooms.
• Avoid wind and smoke when possible.

Artificial tears and lubricants

Over-the-counter artificial tears are the first line of defense. Mayo Clinic recommends preservative-free drops if you need them more than four times a day.

Warm compresses for meibomian glands

For evaporative dry eye, warm compresses help unclog oil glands. Mayo Clinic advises applying a warm, damp cloth to closed eyes for 5–10 minutes daily.

Prescription treatments

If basic measures aren’t enough, prescription options include cyclosporine (Restasis) and lifitegrast (Xiidra). These reduce inflammation on the ocular surface. Mayo Clinic notes they can take weeks to show full effect.

When to see a doctor

If your symptoms persist despite self-care, an eye exam is warranted. The HSE Ireland (national health service) advises seeing a GP or optician if dryness lasts more than a few days.

Bottom line: Patients with mild symptoms: start with artificial tears + screen breaks + warm compresses. Patients with moderate symptoms: add prescription drops and omega-3 supplements. Both groups: if no improvement in 2 weeks, see an eye doctor.

When should you worry about dry eyes?

Most dry eye is a nuisance, but certain symptoms signal something more serious.

Red flags: severe pain, vision changes, redness

Mayo Clinic (leading US medical center) warns that sudden vision changes, severe eye pain, or persistent redness require immediate medical attention. These can indicate corneal damage or infection.

Associated autoimmune conditions

Dry eye can be an early sign of Sjögren’s syndrome, rheumatoid arthritis, or lupus. Mayo Clinic lists these as common associated systemic diseases. If you also have dry mouth or joint pain, an autoimmune workup is wise.

Signs of corneal damage

Chronic severe dry eye can lead to corneal ulcers and scarring. The National Eye Institute (US government research body) states that untreated corneal damage can impair vision permanently.

Bottom line: Any patient with dry eye plus vision change, severe pain, or suspected autoimmune disease should see an ophthalmologist immediately. Otherwise, routine care is safe.

“Dry eye happens when you don’t have enough tears or when your tears evaporate too quickly.”

– Cleveland Clinic (leading US hospital system)

What causes dry eyes all of a sudden?

Sudden-onset dry eye often catches people off guard. The triggers are usually environmental or medication-related.

Environmental triggers

• Low humidity (air-conditioning, indoor heating)
• Smoke, wind, or air pollution
• Prolonged screen use without breaks

Mayo Clinic confirms that dry air and wind increase tear evaporation, so moving from a humid to a dry environment can cause sudden symptoms.

Medication side effects

Many common drugs list dry eye as a side effect. Mayo Clinic and a PMC review (peer-reviewed medical literature) both identify antihistamines, decongestants, blood pressure medications, antidepressants, and hormone therapy as contributors.

Recent eye surgery (LASIK)

LASIK and other refractive surgeries can reduce corneal nerve sensitivity, leading to temporary dry eye. Mayo Clinic notes this usually resolves within months.

Allergic reactions

Allergies cause inflammation of the ocular surface, which disrupts tear film stability. Mayo Clinic includes allergic eye disease as a trigger.

Bottom line: If your dry eyes came on suddenly, check your environment and recent medication changes. If you started a new drug, ask your doctor about alternatives.

Can dry eyes cause blindness?

Directly? Very rarely. But chronic, severe dry eye can damage the cornea enough to impair vision permanently.

Severe dry eye and corneal damage

The cornea depends on tears for oxygen and protection. The National Eye Institute (US government research body) warns that prolonged dryness can lead to corneal abrasions, ulcers, and scarring.

Infections and scarring

When the corneal surface is compromised, bacteria can enter, causing infection and potential vision loss. Mayo Clinic lists corneal ulcers as a complication of untreated dry eye.

Preventive measures

Early treatment prevents progression. Lubrication, anti-inflammatory drops, and addressing underlying causes keep the cornea healthy.

“Risk factors include being over 50, wearing contact lenses, looking at screens for long periods, and air-conditioned environments.”

– HSE Ireland (Irish national health authority)

Bottom line: Blindness from dry eye is rare but real. Patients with severe symptoms, especially those with autoimmune conditions, must stay on top of treatment to avoid corneal damage.

For those seeking relief, exploring the best eye drops for dry eyes can provide targeted moisture and comfort.

Frequently asked questions

For those managing dry eye at home, choosing the right lubricant is critical. We’ve reviewed the best eye drops for dry eye to help you find relief. And if you’re considering an eye exam, our guide on optician availability may be useful — though services have largely returned to normal in most regions.

Dry eye is a signal from your body that something in the tear film is off. For most people, the fix is straightforward: adjust your environment, change your screen habits, and support your tear glands with warm compresses and nutrition. For the minority with underlying autoimmune or nutritional issues, the stakes are higher — catching it early prevents corneal damage. The choice for patients in Ireland and beyond is clear: take symptoms seriously early, or risk a longer, more uncomfortable road later.