Eye Infections and Eye Injuries on Koh Samui

What goes wrong with eyes here ?

Four things, in roughly this order of frequency. Conjunctivitis, from pool water, seawater, shared towels or an ordinary virus. Contact lens problems, which are far more common here than at home for reasons covered below. Corneal abrasions, usually from sand, a stray finger, or a mask strap. And mask squeeze, a pressure injury that looks alarming and is usually less serious than it appears.

Allergy adds to all of them. Sun, salt, sand, air conditioning and chlorine are individually irritating and collectively relentless, which is why a mildly dry eye on day one becomes a genuinely sore one by day four.

Why are contact lenses such a problem on a beach holiday ?

Because almost everything about the environment works against them. Lenses should not be worn in the sea or a pool, and people wear them anyway because the alternative is not being able to see. Water introduces organisms directly against the cornea under a lens that then traps them there, and the resulting infection can be serious in a way ordinary conjunctivitis is not.

Heat and dryness add to it. Air conditioning, wind on a boat, and long days outdoors all dry the eye, which makes lenses sit badly and increases rubbing. Add sand, a tired traveller sleeping in them after a late night, and hands that have been in the sea, and the risk climbs considerably.

What to do instead

• Wear prescription sunglasses or a prescription mask rather than lenses in the water
• Bring glasses as well as lenses, and actually use them
• Never sleep in lenses here, whatever you do at home
• Use fresh solution, never water, and never top up an old case
• Take them out at the first sign of irritation and leave them out
• Replace the case regularly

How do you tell conjunctivitis from something worse ?

The distinguishing features are pain, light sensitivity and vision. Ordinary conjunctivitis is gritty, red and sticky but it does not usually hurt, does not make you avoid light, and does not blur vision once you have blinked the discharge away.

Anyone who wears contact lenses should be assessed rather than treated at home, because the infections associated with lens wear behave differently and can progress quickly.

Why not use leftover drops ?

Because some contain steroids, and steroids given into an eye with an infection or an abrasion can make things considerably worse. Drops left over from a previous episode, borrowed from a friend, or bought without an examination are a recognised way of turning a treatable problem into a serious one.

The same applies to anything soothing you might reach for. Do not put breast milk, tea bags, salt water, or anything else recommended confidently on a beach into an eye. Clean water to flush out a foreign body is the one exception, and that is irrigation rather than treatment.

What is mask squeeze ?

A pressure injury from failing to equalise the air space inside a dive mask. As the diver descends, the air in the mask compresses, and if they do not exhale gently through the nose to replace it, the mask acts as a suction cup on the face.

The result looks dramatic — bloodshot eyes, bruising around the eye sockets, sometimes swelling — and is usually less serious than its appearance suggests. It is painless at the time and discovered in a mirror afterwards. It is still worth being assessed, particularly to confirm vision is unaffected, and it is a signal to work on equalisation technique before the next dive. The related ear and sinus problems usually travel with it.

Dry eyes are not trivial here

The most common complaint of all is simply dryness, and it gets dismissed because it sounds minor. Air conditioning, wind on a boat, long days outdoors, salt and chlorine all strip the tear film, and a dry eye surface is more easily scratched and more easily infected than a healthy one.

Preservative-free artificial tears help considerably and are worth having. Where dryness persists despite them, or where the eye is red as well as dry, come in — persistent dryness occasionally points to something more than the environment, and it is also the state in which a minor scratch becomes a real problem. The broader scope of the Lamai clinic covers what else can be dealt with at the same visit.

What should you do first ?

1. Stop and assess rather than rubbing, which makes an abrasion worse.
2. Remove contact lenses immediately and leave them out.
3. Flush with clean water or saline for a foreign body or a splash.
4. Do not patch the eye shut unless told to.
5. Avoid bright light and screens if it is uncomfortable.
6. Come in for anything involving pain, light sensitivity or vision.

Keep the lens case and the solution if you are a lens wearer, since what you have been using is relevant. The NHS page on conjunctivitis is a reasonable reference for what ordinary conjunctivitis looks like, and the practical detail on being seen is in our guide to seeing a doctor in Lamai.

Sun and the eyes

Eyes burn in the same way skin does, and snow blindness has a tropical equivalent that catches out boat passengers and snorkellers. Hours of reflected glare off water produce a gritty, painful, light-sensitive eye several hours later, which people blame on sand or salt.

Wrap-around sunglasses with genuine UV protection are the fix, and they are more effective than any treatment afterwards. If you have spent a long day on the water and both eyes are painful and light-sensitive that evening, come in rather than assuming it will pass — see also the broader guidance on sunburn, which frequently arrives on the same day from the same trip.

Should you be seen ?

• Pain, light sensitivity or reduced vision → same day, without exception
• Red eye in a contact lens wearer → same day
• Something in the eye that will not flush out → same day
• Chemical splash → flush for twenty minutes, then same day
• Bloodshot eyes after diving, vision normal → worth checking, not an emergency
• Gritty sticky eyes, no pain, vision fine → likely conjunctivitis; come in if it worsens