Sunglasses for swimming: why you need goggles, and what sunglasses are for

Sunglasses are not swimming eyewear, and the thing you probably want is tinted goggles. That is an actual product category, widely available, and most people who swim outdoors have never considered it.

Sunglasses fall off, they do not seal, their coatings do not survive chlorine or salt, and in open water a lost pair is lost permanently. Goggles solve the same problem properly.

Why a swim needs eye protection at all

Water reflects. Light arriving at a shallow angle reflects strongly off a water surface, and when you are swimming your eyes are at surface level — so the reflection comes directly at you. This is why open water in bright sun is one of the highest-glare environments there is, and why the beach advice in best sunglasses for the beach emphasises reflection from below.

UV exposure is high, from above and from the surface, and it is easy to underestimate because the water keeps you cool.

Navigation becomes impossible into low sun. Open water swimmers sight on a buoy or landmark every few strokes, and a low sun on the water removes the ability to see anything at all in that direction. This is a safety matter, not comfort.

Chlorine irritates. Pool water causes red, stinging eyes directly, and the irritant is largely chloramines formed when chlorine reacts with organic matter rather than chlorine itself.

What to use in the water

Tinted goggles. Smoke, grey or brown tints, exactly the same logic as sunglasses — grey for neutral dimming, brown for contrast. Widely available and inexpensive.

Mirrored goggles. The usual choice for bright outdoor conditions. The mirror coating reflects a proportion of light before it enters, so these are the darkest common option, and they are what competitive open water swimmers use in sun.

Polarized goggles. They exist and are much less common. The theory is sound — surface glare is polarised — and in practice the mirror approach dominates the market. If you can find polarized and you swim in bright conditions, they are worth trying.

Clear goggles for pools, indoor swimming, dawn and dusk, and overcast days. Do not wear dark goggles in a dim pool; the same logic as not wearing sunglasses at night.

Two pairs if you swim outdoors regularly: clear and mirrored. They cost very little and the right one makes a real difference.

Prescription goggles are a real product, both off-the-shelf in standard powers and made to prescription. For anyone who swims in open water and cannot see a buoy without correction, this is a straightforward safety purchase. The broader options are in are prescription sunglasses worth it.

What sunglasses are for

The poolside, the beach, the walk to the water, and the hours afterwards.

That is not a trivial role. Most of a day at a pool or a lake is spent out of the water, in high reflected light, and this is where a proper pair earns its place. Grey or brown, polarized, with side coverage.

Polarized is genuinely good here because you are looking at water. It cuts the surface glare and lets you see into the water — useful for watching children, and the same reason it helps for fishing. See polarized vs non-polarized and best lens colour for fishing.

A retainer matters here more than almost anywhere. Leaning over water, bending to pick something up, a child grabbing at your face — all common, and a pair in the water is often gone. Sunglasses straps and retainers covers types that handle wet conditions.

A brimmed hat for the overhead sun no lens reaches — see sunglasses and hats.

What chlorine and salt do to sunglasses

Relevant because sunglasses end up near water whether or not they go in it.

Chlorine attacks coatings. Anti-reflective and mirror coatings are thin films, and chlorinated water degrades them. The visible result is clouding, patchiness or a rainbow sheen that cannot be cleaned off, and it is permanent.

Salt is mechanically damaging as it dries. Salt crystallises out as water evaporates, and dried salt crystals on a lens are abrasive — so the next wipe scratches. In hinges, the crystals cause the grinding covered in squeaking sunglasses hinges, and in the lens groove they work a lens loose, as in when a sunglasses lens pops out. Our sunglasses and salt water piece covers the full picture.

Both attack frame hardware. Steel screws and spring hinges corrode, and a corroded screw is one you cannot remove to service.

The fix is a rinse in fresh water, every time, including the hinges, followed by drying with a microfibre cloth rather than leaving them to air dry with salt still dissolved in the drops. Thirty seconds, and it is the difference between a pair that survives a summer and one that does not.

Contact lenses and water

Worth a direct warning because it is common and the risk is real.

Do not swim in contact lenses without sealed goggles. Water — pool, lake, sea or tap — can carry organisms including Acanthamoeba, and a contact lens traps them against the cornea. Acanthamoeba keratitis is rare, extremely painful, and can cause lasting vision loss.

If you swim in lenses, use well-sealed goggles, and if water does get in, remove and discard the lenses rather than reusing them.

Daily disposables are the lower-risk option for swimmers, because you throw them away afterwards.

Better still: prescription goggles, no lenses.

After the swim

Rinse your eyes with clean water or saline if they are stinging from chlorine, and do not rub.

Expect some redness after pool swimming; it should settle within an hour or two.

Light sensitivity afterwards is common after a bright day on water, and it is usually ordinary fatigue. Sunglasses for the journey home are a sensible idea — and if it persists into the next day, or there is pain, that is worth a doctor. Photokeratitis, essentially sunburn of the cornea, happens on water as well as snow.

See someone the same day for eye pain, vision changes, persistent redness, or anything that feels like grit after swimming in natural water. The contact lens risk above is the reason to take this seriously.

Fogging, and the trick that works

The most common complaint about swimming goggles, and worth solving because fogged goggles in open water are a navigation problem rather than an annoyance.

Why it happens: warm humid air inside the goggle meets a lens cooled by the water, and condensation forms on the inside surface.

What works:

Anti-fog coating, which most goggles have when new and which wears off. Do not rub the inside of the lens — that is what removes it. Rinse and let them dry instead.

A drop of baby shampoo diluted in water, smeared thinly inside and rinsed lightly. The standard swimmer's fix, and it works by breaking surface tension so condensation forms a film rather than droplets.

Spit, which does the same thing less elegantly and is always available.

Not toothpaste, which is abrasive and will scratch the lens.

Getting the fit right. A goggle that leaks slightly fogs more, because the temperature difference is larger. Seals should sit on bone around the eye socket, not on soft tissue.

Store them dry and separated, not stacked lens-to-lens in a wet bag, which is how coatings get rubbed off.

Children in the water

Worth its own note, because the exposure is high and the compliance is low.

Goggles, not sunglasses, and that is easier with children than with adults — goggles are normal pool equipment and nobody argues about them.

Clear goggles for pools, tinted or mirrored for bright open water.

Out of the water, a strap is what makes sunglasses work on a child at all, and the UV specification matters more for children because a young lens filters less short-wavelength light than an adult's. Sunglasses for babies and toddlers covers it.

Reflected light off water and pale poolside is a large part of the exposure, and a brimmed hat handles the overhead half.

Frequently asked questions

The short version

Goggles for the water, sunglasses for everywhere else. Tinted or mirrored goggles are the product you are looking for, and clear ones for dim conditions.

Polarized sunglasses for the poolside, with a retainer and a hat — you are looking at water for hours.

Rinse everything in fresh water afterwards. Chlorine ruins coatings permanently and salt scratches lenses as it dries.

And do not swim in contact lenses without sealed goggles. That one is about your cornea, not your eyewear.