What Is Dry Eye?
Dry Eye is a chronic and often progressive condition in which the eyes do not produce enough tears, or the tears produced are unable to adequately protect and nourish the eye. This usually occurs because the tear film becomes unstable, leading to irritation, inflammation, blurred vision, and discomfort.
Despite its name, Dry Eye is not simply about a lack of tears. In many cases, people with dry eye actually produce tears, but those tears evaporate too quickly or lack the correct balance of components needed to keep the eye surface healthy.
Dry eye can affect people of all ages and lifestyles and is increasingly common in modern society.
Understanding the Tear Film
A healthy tear film has three essential layers:
Oil (lipid) layer
Produced by the meibomian glands in the eyelids. This layer prevents tears from evaporating too quickly.
Water (aqueous) layer
Produced by the lacrimal glands. This layer hydrates the eye, delivers oxygen and nutrients, and washes away debris.
Mucus layer
Helps tears spread evenly across the surface of the eye and adhere to the cornea.
If any one of these layers is disrupted, the tear film becomes unstable, leading to dry eye symptoms.
What Causes Dry Eye?
Dry eye is multifactorial, meaning it rarely has just one cause. It usually develops due to a combination of lifestyle habits, environmental exposure, eyelid dysfunction, systemic health factors, and inflammation.
Lifestyle Factors That Contribute to Dry Eye
Prolonged Screen Use
Modern digital lifestyles are one of the biggest contributors to dry eye.
- Reduced blink rate when using computers, phones, or tablets
- Increased incomplete blinking
- Poor distribution of tear film oils
- Symptoms worsen throughout the day
Contact Lens Wear
- Disrupts the natural tear film
- Increases tear evaporation
- Can exacerbate underlying dry eye disease
- Discomfort often increases with prolonged wear
Sleep Issues
- Poor sleep quality reduces tear production
- Incomplete eyelid closure during sleep can worsen dryness
- Fatigue contributes to inflammation and eye strain
Cosmetics and Eyelid Hygiene
- Makeup debris can block oil glands
- Incomplete makeup removal contributes to inflammation
- Lash extensions and heavy eyeliner can worsen symptoms
Occupational Risk Factors
Certain professions increase dry eye risk due to visual demands and environmental exposure:
- Office and computer-based work
- IT professionals and gamers
- Drivers, pilots, and transport workers
- Healthcare workers (including mask-associated dry eye)
- Teachers and lecturers
- Tradespeople and outdoor workers
- Manufacturing and warehouse environments
Environmental Factors
Dry or Air-Conditioned Environments
- Low humidity accelerates tear evaporation
- Common in offices, homes, and vehicle
Wind and Outdoor Exposure
- Wind dries the ocular surface
- Increases tear instability
Air Travel
- Aircraft cabins have extremely low humidity
- Symptoms often worsen during and after flights
Pollution and Smoke
- Irritates the ocular surface
- Triggers inflammation
- Worsens chronic dry eye
Eyelid and Gland-Related Causes
Meibomian Gland Dysfunction (MGD)
One of the most common causes of dry eye.
- Oil glands become blocked or dysfunctional
- Poor-quality oil leads to rapid tear evaporation
- Often worsened by screen use and inflammation
Blepharitis
- Chronic inflammation of the eyelid margins
- Caused by bacteria or Demodex mites
- Disrupts tear film stability and gland function
Incomplete or Infrequent Blinking
- Common with digital device use
- Prevents proper oil release and tear distribution
Medical and Hormonal Contributors
Eye Surgeries
Certain eye surgeries can contribute to the development or worsening of dry eye disease. Procedures such as;
- Cataract surgery,
- Laser vision correction (including LASIK and PRK)
- Eyelid surgeries
can temporarily or, in some cases, persistently disrupt the delicate balance of the tear film.
During surgery, corneal nerves may be affected, reducing the eye’s natural ability to sense dryness and stimulate tear production. In addition, inflammation, changes in blinking patterns, or alterations in eyelid position after surgery can interfere with proper tear distribution and drainage.
While these procedures are often highly successful and vision-improving, it is important for patients to understand that dry eye symptoms. such as irritation, burning, or fluctuating vision, can occur afterward and may require targeted treatment and ongoing management.
Allergies
Allergies can significantly contribute to dry eye symptoms by causing inflammation on the surface of the eyes.
When the eyes are exposed to allergens such as pollen, dust, or pet dander, the immune system releases inflammatory substances that can disrupt the tear film and reduce tear quality. This inflammation may lead to increased tear evaporation and irritation, making the eyes feel dry, itchy, red, or watery.
Frequent eye rubbing, which is common with allergies, can further damage the tear film and worsen dryness. Over time, untreated eye allergies can aggravate or trigger chronic dry eye disease, making proper diagnosis and management of both conditions essential for lasting relief.
Other health factors
Dry eye is more common in people with:
- Increasing age
- Menopause or hormonal changes
- Pregnancy
- Autoimmune conditions (e.g. Sjögren’s syndrome)
- Thyroid disease
- Diabetes
- Rosacea
- Long-term medication use (antihistamines, antidepressants, beta blockers, acne medications)
Symptoms of Dry Eye
Dry eye symptoms can vary significantly between individuals and may fluctuate throughout the day.
Common Sensations
- Dryness
- Burning or stinging
- Gritty or sandy feeling
- Foreign body sensation
- Tight or sore eyes
Visual Symptoms
- Blurred or fluctuating vision
- Vision that worsens with reading or screen use
- Difficulty focusing
- Eye fatigue or strain
Redness and Inflammation
- Red or bloodshot eyes
- Swollen eyelid
- Sensitivity to light
- Irritated or heavy eyelids
Watery Eyes
Paradoxically, dry eye can cause excessive tearing due to reflex tearing triggered by irritation.
Styes and Chalazia: Important Warning Signs
Styes (Hordeola)
- Painful, red eyelid lumps
- Caused by infected oil glands
- Often linked to blepharitis and MGD
Chalazia
- Painless eyelid lumps
- Caused by blocked meibomian glands
- Can become chronic or recurrent
Frequent styes or chalazia are often a sign of underlying dry eye and eyelid dysfunction.
Other Often Overlooked Symptoms
Dry eye can also present as:
- Itching
- Mucus discharge
- Difficulty opening eyes upon waking
- Difficulty wearing contact lenses
- Increased blinking
- Eye rubbing
- Headaches related to eye strain
- Discomfort that worsens later in the day
Why Dry Eye Is Often Missed
Many patients:
- Assume symptoms are normal
- Self-treat with artificial tears alone
- Are told their eyes “look fine” during basic exams
Dry eye requires specialised evaluation to identify the underlying cause and guide effective treatment.
Why Early Diagnosis Matters
Without treatment, dry eye can lead to:
- Chronic inflammation
- Progressive gland damage
- Increased risk of infections
- Recurrent styes and chalazia
- Reduced quality of life
- Impact on work, driving, and daily activities
Early diagnosis allows for targeted treatment and helps prevent long-term damage.
Dry Eye Is a Complex, Whole-Eye Condition
Dry Eye is far more than occasional dryness. It is a chronic condition influenced by lifestyle, environment, eyelid health, and systemic factors, with symptoms that affect comfort, vision, and daily life.
With comprehensive assessment and modern treatment options, dry eye can be effectively managed. Restoring comfort, clarity, and confidence.
