Dry eye on the coast: wind, salt and air conditioning

People move to Mazarrón for the climate and end up at the optician’s because of the climate. It is not a contradiction: the very conditions that make it pleasant to live here — the gentle wind, the constant sun and the sea two hundred metres away — are hard on the surface of the eye.

Dry eye is the most frequent ocular complaint we see from May to October, and the one most people have been putting up with for years without giving it a name.

What dry eye is

The surface of the eye is covered by a tear film, a very thin layer with three components: water, mucin and an oily layer that stops the water evaporating. If that film is not produced in sufficient quantity, or if its quality is poor, the surface is left exposed. That is dry eye.

The American Academy of Ophthalmology sums it up in two scenarios: the eyes do not produce enough tears, or the tears they produce are not of the right quality.

The symptom that confuses people most is the opposite of the expected one: many dry eyes water. When the surface becomes irritated, the eye triggers a reflex tearing, copious and watery, which does not have the right composition and which runs down the cheek without doing its job. If your eyes water in the wind and then feel rough, it is not that your eyes are wet. It is quite the opposite.

The four coastal factors

The wind

It is the most obvious and the most underestimated. Moving air carries off the tear film by evaporation, and on the coastal strip there is wind almost every day.

The American Academy of Ophthalmology recommends protecting yourself from dry wind with wraparound glasses when you go out. It is not an aesthetic recommendation. A frame that closes at the sides cuts off the draught passing in front of the eye.

Here that means: on the seafront, at the beach, on the boat and on the golf course. And with the car window down, which is the worst of all.

Salt spray

Near the breaking waves, the air carries microdroplets of seawater in suspension. The salt left on the ocular surface raises the osmolarity of the tears, which is precisely the mechanism that sustains the dry-eye circle: the more concentrated the tears, the more the epithelium is irritated, and the more irritated the epithelium is, the worse the tears it produces.

After a while at the beach in the wind, a rinse with artificial tears does more than rubbing your eyes, which is what everybody does and what helps least.

Air conditioning

From June to September, life here is lived with the air conditioning on. The American Academy of Ophthalmology includes among the environmental causes of dry eye: fans, car air vents, recirculated aircraft air and draughts from air conditioning.

The two worst places are the car, where the vent points straight at your face, and the bedroom with the unit on all night. Eight hours of dry air over closed eyes that are not blinking explains why so many people wake up with their eyes stuck together and gritty.

And there is a factor peculiar to our resident patients: flights. Anyone who travels back and forth several times a year to the United Kingdom, Germany or France spends many hours in the driest cabin an ordinary person is exposed to.

The sun and the hours outdoors

Here it is not just about radiation. It is that life happens outside. More hours in the open air are more hours of evaporation, and a high ambient temperature speeds that process up.

What age adds

The climate explains why it is more common here. Age explains why it starts.

Tear production decreases over the years. In women, the hormonal changes of the menopause are frequently associated with the appearance of ocular dryness. And there are medicines in everyday use — among them antihistamines, decongestants, diuretics, antidepressants and some blood-pressure treatments — that can reduce tear secretion.

If you started a new treatment and noticed dry eyes a few weeks later, say so at your appointment. Do not stop any medication on your own initiative.

How to choose artificial tears

It is the most confusing shelf in any chemist’s. Three criteria are enough.

1. With or without preservatives

The preservative stops the bottle becoming contaminated, but it irritates the ocular surface with repeated use. The American Academy of Ophthalmology sets the threshold: if you use drops more than six times a day, or if you are allergic to preservatives, use preservative-free ones. Other sources from the same academy lower that threshold to four times a day.

In practice, almost anyone with genuine dry eye ends up going beyond four applications a day. Our default recommendation is to start preservative-free straight away: single-dose vials, or a bottle with a valve that needs no preservative.

They cost more. But a dry eye treated with drops that irritate it is a dry eye that does not improve, and that is the real expense.

2. With or without phosphates

Here it is worth being precise, because alarmist versions circulate.

Phosphates are used as a buffer in roughly a third of eye drops in the European Union. The European Medicines Agency reviewed the cases of corneal calcification associated with their use and concluded two things. First: the cases are extremely rare in relation to the millions of packs distributed. Second: patients with no previous corneal damage do not appear to be at significant risk; the problem has been described in corneas that were already severely damaged, for example after a chemical burn.

The regulator did not restrict their use. Translated to your case: if you have a healthy ocular surface and ordinary dry eye, phosphates are not your problem. If you have a compromised cornea — and you will know if you have been told anything of the sort — choose a phosphate-free product and ask about it.

3. The thickness

• Light drops for daytime. They do not blur and they can be repeated as often as needed.
• Gels for the hardest hours, or for anyone who spends the afternoon in the wind. They last longer and blur slightly when applied.
• Ointment for night-time only. It blurs a good deal and you cannot drive afterwards.

An eye that dries out at night needs something thick at eleven o’clock, not more light drops during the day.

Five things that help and cost nothing

• Angle the car air vent downwards or towards the windscreen.
• Turn the bedroom air conditioning off an hour before bed, or raise the set temperature.
• Local warmth on the eyelids: five minutes with a warm cloth and a gentle massage of the lid margin, at night. It helps when the problem is in the glands that produce the oily layer, which is the most frequent case.
• Blink completely. In front of a screen we blink a third as often as normal, and half a blink does not spread the tears.
• Wraparound sunglasses for the seafront walk.

What not to do

• Drops that “take the red out”. Vasoconstrictors whiten the eye by narrowing the vessels, they do not treat dryness, and when you stop them the redness usually comes back stronger.
• Rubbing. It relieves for two seconds and makes the rest of the day worse.
• Home washes with camomile, kitchen saline or bottled drinking seawater.
• Carrying on with contact lenses as if nothing were happening. A dry eye with lenses in is a dry eye with less oxygen and more friction.
• Sharing the bottle with your partner.

When it needs looking at

Book an appointment if the dryness lasts more than a few weeks despite the drops, if your eyelids feel stuck on waking, if your vision fluctuates through the day, or if the edges of your eyelids are red and crusted.

And come without waiting if severe pain, marked sensitivity to light or loss of vision appears. That is no longer dry eye.

At the examination we assess the quality of the tear film and the condition of the eyelids. From that we decide which type of tear suits you and how often, and we observe signs that require ophthalmological assessment where there are any. Very often the outcome is a change of routine and a cheaper product than the one you were already buying.