Dry eye affects approximately 20% of New Zealand adults, making it one of the most prevalent eye conditions in the country. What makes that figure significant is not just its size, but the gap beneath it: a large proportion of people with measurable dry eye signs have never been diagnosed, because their symptoms point them toward other explanations. Understanding what dry eye actually is, and why it so often goes unrecognised, is the first step toward managing it properly.
What dry eye actually is
Dry eye is a condition where the tear film fails to keep the surface of the eye adequately lubricated. This happens in one of two ways: either the eye produces too few tears (known as aqueous tear deficiency), or tears evaporate too quickly because the oil layer that seals the tear film is thin or inconsistent. The second type, evaporative dry eye, is caused by meibomian gland dysfunction, where the small oil-producing glands along the eyelid margins become blocked or underperform. Both types can occur together, and both respond differently to treatment, which is why an accurate assessment matters more than self-managing with drops alone.
Symptoms that are easy to overlook
Dry eye symptoms are frequently attributed to tiredness, screen use or seasonal allergies, which is one of the main reasons the condition goes undiagnosed for so long. The symptoms themselves are often intermittent, which makes it easy to dismiss them as temporary.
Common symptoms include:
- A gritty or sandy sensation in the eye
- Burning or stinging
- Blurred or fluctuating vision, particularly toward the end of the day
- Light sensitivity
- Redness of the eye or eyelids
- A feeling that something is caught in the eye
- Excessive watering or teary eyes
- Discomfort or reduced tolerance when wearing contact lenses
The watery eye symptom is worth pausing on. Excessively teary eyes are often seen as the opposite of dry eye, but they can be a direct response to it. When the ocular surface becomes irritated from an unstable tear film, the eye produces a flood of reflex tears in response. Those tears do not have the same protective quality as a stable tear film and do not resolve the underlying problem.
How common is dry eye in New Zealand
Around one in five New Zealand adults lives with dry eye, but the true burden of the condition is likely broader than that figure captures. Research from the New Zealand National Eye Centre at the University of Auckland found that clinical signs of dry eye were present in almost half of a cohort of 45-year-old New Zealanders, yet only 9% of participants met the full diagnostic criteria for dry eye disease. A further 37% had measurable ocular surface changes with no symptoms at all.
That gap between signs and symptoms is clinically significant. It means a substantial number of people are experiencing changes to their tear film and ocular surface without yet feeling them clearly enough to seek help. By the time symptoms become persistent, the condition has often been progressing for some time.
Dry eye is not confined to older adults. Research from the same group shows that clinical signs of meibomian gland dysfunction begin to appear in people as young as their mid-30s, with tear film instability and other dry eye markers typically emerging between the ages of 33 and 38. For people in that age group who spend long hours on screens, the risk is compounded further.
Why New Zealand creates the right conditions for dry eye
Several environmental and lifestyle factors that are particularly common in New Zealand contribute to dry eye. Some are modifiable, some are not, but all are worth understanding.
Screen time and reduced blinking
When a person focuses on a screen, the blink rate drops from a typical 15 to 17 blinks per minute to as few as 5 to 7. Each blink spreads the tear film across the ocular surface, so a reduced blink rate accelerates evaporation and destabilises the tear film. This applies equally to phones, tablets, computers and televisions. It affects children and younger adults as much as older populations and is one of the key reasons dry eye is no longer a condition associated primarily with age.
The Canterbury climate and the nor’west wind
The Canterbury nor’wester is a hot, dry foehn wind that strips moisture from the air and significantly accelerates tear evaporation from the ocular surface. Combined with Christchurch’s already variable humidity and strong UV exposure, the regional climate creates conditions that worsen dry eye symptoms and can trigger flare-ups in people who are otherwise well-managed. For Cantabrians, seasonal changes in wind and temperature are a genuine contributing factor to how their eyes feel day to day.
Indoor environments
Heating systems, heat pumps and air conditioning all reduce ambient humidity, which speeds up tear film evaporation. Open-plan offices with centralised climate control are a particularly relevant environment, as employees spend extended hours in low-humidity conditions while simultaneously using screens. The combination of both factors in a single environment creates a meaningful cumulative effect on the tear film.
Contact lens wear
Contact lenses sit directly on the tear film and can disrupt its stability and rate of evaporation. People who wear lenses and find they become uncomfortable toward the end of the day, or who notice their tolerance for lenses has reduced over time, may be experiencing dry eye rather than a problem specific to their lens brand or type. A dry eye assessment can clarify whether the ocular surface is a contributing factor before any decision is made to change lenses. The Groovy Glasses contact lenses page covers fitting and lens options in more detail.
Hormonal changes and medications
Dry eye is more prevalent in women, and the risk increases during perimenopause and menopause when declining oestrogen levels affect both the quantity and quality of tear production. Several commonly used medications also contribute to dry eye, including antihistamines, antidepressants, some blood pressure medications and oral contraceptives. People taking any of these who experience eye discomfort should raise it at their next eye exam, as medication-related dry eye often requires a tailored management approach.
Who is at higher risk
Some risk factors for dry eye are modifiable, others are not. Knowing which category applies helps in understanding both the likely cause and the most useful management approach.
| Risk factor | Why it matters |
| Age over 40 | Each decade of life is associated with a 25% increase in the odds of developing dry eye |
| Female sex | Hormonal changes during menopause and from contraceptive use affect tear production and quality |
| East Asian ethnicity | Identified as a significant non-modifiable risk factor in New Zealand and international research |
| Contact lens wear | Lenses disrupt the tear film and can accelerate evaporation over the course of the day |
| Extended screen use | Reduces blink rate, increasing tear film evaporation |
| Antihistamines or antidepressants | These medications reduce aqueous tear production |
| Thyroid disease | Associated with meibomian gland dysfunction in New Zealand research |
| Rheumatological conditions | Including Sjögren syndrome and rheumatoid arthritis, which reduce tear secretion |
| Low-humidity environments | Air conditioning, heating and wind all accelerate evaporation from the tear film |
Why dry eye so often goes undiagnosed
Dry eye signs can be present and measurable before symptoms become obvious or consistent. As noted above, New Zealand research found that 37% of a representative cohort had ocular surface disease with no symptoms at all. For those who do experience symptoms, the most common response is to attribute them to tiredness, allergies or screen use and manage them with over-the-counter eye drops. Drops can relieve discomfort temporarily but do not address the underlying cause, and because the two main types of dry eye require different approaches, using the wrong treatment does little to slow the progression of the condition.
What a dry eye assessment involves
A dry eye assessment goes beyond what a standard eye exam covers. The optometrist evaluates the quality and stability of the tear film, the function of the meibomian glands in the eyelids, and the condition of the ocular surface for signs of damage or inflammation. The aim is to identify which type of dry eye is present before recommending a management plan, because aqueous deficiency and evaporative dry eye respond to different treatments.
