What is dry eye, and why do watery eyes count

What it feels like day to day

Your eyes are fine first thing, then gritty by mid-afternoon at the laptop. Reading blurs for a moment and clears when you blink. The wind on the walk home makes them sting, and some evenings they feel heavy and tired for no reason. If that sounds familiar, you are describing dry eye, not a problem with your glasses.

Healthify NZ lists the usual symptoms as stinging or burning, a gritty or sandy feeling, sensitivity to light, redness, blurred vision that comes and goes, heavy or tired eyes, and reduced tolerance of reading or screen work. Contact lenses can become uncomfortable, and some people notice trouble driving at night.

Two patterns are worth knowing. Dry eye is almost always a both-eyes condition, and it is chronic. The TFOS DEWS III diagnostic report notes that symptoms that start suddenly, or that are much worse in one eye, point to something else, such as infection or injury, and need a different kind of appointment.

Two types, and the oil glands that matter most

Your tear film has three layers. The American Academy of Ophthalmology describes an inner mucus layer that helps tears stick to the eye, a watery middle layer made by the lacrimal gland, and an outer oily layer made by the meibomian glands along the edges of your eyelids. The oil keeps the surface smooth and stops the watery layer drying out too quickly.

That gives two broad types. In aqueous-deficient dry eye, the lacrimal gland does not make enough of the watery layer. In evaporative dry eye, there is enough water but the oil layer is poor, so tears evaporate too fast. The AAO calls meibomian gland dysfunction, where the oil glands become blocked or inflamed and the oil turns thick, a major cause of the evaporative type. Many people have a mix of both.

This is why the type matters. A drop that adds water does little for a blocked oil gland, and warming the eyelids does little for a gland that is not making water. The Tear Film and Ocular Surface Society's 2025 DEWS III reports define dry eye as a multifactorial, symptomatic disease in which the tear film or eye surface has lost its balance, and they build treatment around which part has failed.

Why watery eyes can still be dry eyes

It sounds backwards, but eyes that stream in the wind or well up at the supermarket are a common sign of dry eye. Healthify NZ puts it simply: the irritation of dry eye may trigger excessive tears. The AAO says the same, that your eyes make more tears when they are irritated by dryness.

These reflex tears are mostly water. They lack the oil and balance of a healthy tear film, so they run off the eye instead of staying on it, and the surface feels dry again within minutes. If your eyes water and sting at the same time, that combination is a clue worth mentioning at your appointment.

Who tends to get it

Anyone can have dry eye, but Healthify NZ, the AAO and the NHS list the same groups as more likely to be affected. Dry eye is common with age and more common in women, with hormonal changes around pregnancy, the contraceptive pill and menopause mentioned by Healthify. Other common contributors are:

• Screens. Healthify NZ notes that screen users blink less often and take more partial blinks, and the AAO lists long periods of computer use among the risk factors. A full blink is what squeezes oil out of the eyelid glands.
• Medicines. Healthify lists antihistamines, decongestants, some antidepressants, some blood pressure medicines, isotretinoin for acne, the contraceptive pill and certain glaucoma drops. Do not stop a prescribed medicine on your own; ask your GP or optometrist first.
• Health conditions. Sjögren's disease, rheumatoid arthritis, rosacea, thyroid disease, diabetes and other immune conditions, as well as blepharitis, the inflammation of the eyelid edges that Healthify calls one of the most common causes of dry eye.
• Environment. Wind, sun, smoke, dust, air-conditioned or heated rooms, and long flights.
• Contact lenses and eye surgery. The AAO lists long-term contact lens wear and laser eye surgery such as LASIK.

What usually helps, and when it is time to be seen

For mild dry eye, Healthify NZ suggests starting at home: a heated wheat bag or eye mask on closed lids for about ten minutes, followed by a gentle massage of the lids towards the lashes, done regularly over the long term. Lubricating drops, gels or ointments can help; ask which suits your type, and consider a preservative-free product if you are using drops more than four times a day. Healthify also suggests ten full blinks after every twenty minutes or so of screen work.

Healthify's advice is to see a healthcare provider if your dry eye persists for 7 to 10 days despite treatment. In New Zealand you do not need a referral to see an optometrist. A comprehensive dry eye evaluation at NVISION works out whether the problem is too few tears, a poor oil layer or both, and the fee is listed on our consultation fees page.

If drops and warm compresses are not enough, the options are compared in our guide to eye drops versus in-clinic dry eye treatment, and the questions to ask before any dry eye treatment are worth reading before you book. Our dry eye questionnaire is a quick way to score your symptoms first. For more background, see our dry eye syndrome page, the causes of dry eye disease and our dry eye FAQs.

When an optometry appointment is the wrong place

Dry eye is uncomfortable but it is not an emergency. Some symptoms that feel similar are. Healthify NZ and the NHS both say to get urgent care rather than wait for a routine appointment if you have a painful red eye, if light hurts your eye, if your vision has changed or dropped, or if there is coloured discharge and your lids are stuck shut in the morning.

Call 111 or go to the nearest hospital emergency department for sudden loss of vision, a shadow or curtain across part of your vision, flashes of light with a sudden shower of new floaters, a chemical splash (Healthify says flush with clean running water for at least 15 minutes first), a red and painful eye with light sensitivity, or any injury to the eye. Do not drive yourself.

Your GP is the right first call if you suspect a condition such as Sjögren's disease or rheumatoid arthritis behind the dryness, or if a prescribed medicine may be the cause. Severe dry eye that does not respond to treatment can be referred to a hospital eye clinic by a GP or optometrist. For advice at any hour, Healthline is free on 0800 611 116.