Seeing Sharp On and Under the Water: Glasses, Lenses and Water Sports in Bali

In Bali the sea is never far. Surf at first light, snorkelling in the afternoon, the boat across to Nusa Penida at the weekend. If you wear a correction, the same question comes back every time, in Canggu as in Sanur: how do you see sharp without leaving your pair at the bottom of the ocean.

We get asked this every day, and it is the question optician blogs cover least. Most advice assumes you live far from water. Here it is the opposite. So let us take the subject properly, because there are two distinct problems hiding behind one question, and the answers are not the same.

In the water, on the water: two problems with nothing in common

In the water, your problem is sharpness. Reading the wave coming, finding your things on the beach, recognising a face. Light comes second.

On the water, in a boat or sitting on a board between sets, the problem becomes light. The surface throws part of the sun's radiation straight back at your eyes, on top of what comes from the sky. You squint, you tire, you read the swell less well.

Confusing the two means buying the wrong pair. Let us take each case.

Swimming with a correction: what an optician will actually tell you

The most common answer is still the soft daily lens. It corrects, it does not move, and you throw it away on the way out. But one rule comes back every time, in Canggu as in Ubud, and it is not negotiable.

A lens is a microscopic sponge sitting on the cornea. Put it in contact with sea water, a pool or a rice field and it holds on to the micro-organisms in there, keeping them against the eye for hours. That is the mechanism behind keratitis, an inflammation of the cornea that can take a long time to treat. The risk is low in absolute terms, but it is avoidable, which is not the same thing. Our guide to contact lens hygiene covers the daily handling rules.

Two clean ways to do it:

• Daily lenses under watertight swimming goggles. Water never touches the lens. You take them out and bin them when you come out. This is the safest method.
• A mask or swimming goggles made to your correction. No lens at all. The correction sits in the mask itself. For regular snorkelling this is by far the best option, and nobody ever thinks to ask for it.

If your correction is moderate, it is worth knowing that an ordinary diving mask slightly improves underwater vision on its own: the layer of air between the eye and the glass changes the path of the light. It does not replace a correction, but it explains why some short-sighted people see the fish better than the sign on the warung.

On a boat: why polarised is not a gadget

Light bouncing off a flat surface, water in particular, becomes polarised: its waves line up in the same horizontal plane. A polarised lens carries a filter that blocks precisely that plane. The white veil disappears and you get back the relief, the colours, sometimes even the bottom.

On the water, the gap with a plain tinted lens is obvious, far more than in town. It is also a real safety gain if you are steering a boat or watching for a set. We go into the mechanism in polarized lenses or UV protection.

Two useful clarifications:

• Polarisation and UV protection are two different things. A lens can be polarised without filtering ultraviolet properly, and the reverse is true too. You want both.
• For full Balinese sun bouncing off water, category 3 is the right level. Category 4, very dark, is designed for high mountains and is not legal for driving. The full scale is in sunglasses lens categories, from 0 to 4.

The frame that holds, and survives the salt

A beautiful pair that does not hold is a lost pair. A few simple principles, learned from repairing glasses that came back from the beach.

• A floating cord, not a decorative one. If it does not float, all it buys you is a clear view of your pair sinking.
• A light, flexible frame. On the water, acetate takes knocks better than fine metal, which bends out of true at the first snag.
• Nose pads that grip. Wet skin and sunscreen make an ice rink. Silicone pads change everything.
• No exposed screw hinges if you can avoid them. Salt gets in and seizes the mechanism.

After the session: three gestures, two minutes

Salt does not forgive. It crystallises as it dries and attacks both the lens coatings and the screws.

1. Rinse in lukewarm fresh water, never hot, as soon as you are back. Without rubbing.
2. A drop of neutral soap on your fingertips, then rinse. Soap lifts the sunscreen, which is far more aggressive on coatings than the salt itself.
3. Dry with a clean microfibre, never a t-shirt or a beach towel, both of which carry sand.

And never leave a pair on the dashboard of a car or a boat. Heat warps acetate in a few hours. More on the local climate in your glasses in the tropics.

What we recommend, depending on how you use the water

• Regular surfing with a correction: dailies under swimming goggles, or nothing in the water and a polarised prescription sun pair for the rest of the day. We cover those in prescription sunglasses in Bali.
• Snorkelling: a mask made to your correction. The best value of the lot.
• Boat, fishing, a day at sea: polarised category 3, floating cord, acetate frame.
• Beach and pool without swimming: your usual sun pair is fine, with the rinsing ritual.

The best pair for the water is not the most technical one. It is the one you are still wearing at the end of the season.

If you are torn between these options, come to Canggu, Ubud or Sanur. An optometrist on site looks at your correction, how you use the water and your face, and we settle it together in a few minutes. Faster than three evenings of research online.

This article is informative and does not replace medical advice. In case of redness, pain, blurred vision or unusual light sensitivity after contact with water, remove your lenses and consult a health professional without delay.