You already know not to wipe your sunglasses on your shirt. Most runners do it anyway. But the shirt wipe is the damage you can see coming. The damage you probably do not see is the one that matters more: it comes from the cleaning spray you bought specifically to look after your lenses.
Most commercial lens cleaning sprays rely on isopropyl alcohol (IPA), which can slowly degrade AR coatings, polarised films, and hydrophobic layers over time. The lens looks fine after a single spray. After months of use, the signs arrive: haziness, crazing, or a film that will not wipe off. By then, the coating is already compromised.
Knowing how to clean sunglasses properly takes about two minutes. Knowing what to avoid takes less. Here is both.
Why Running Sunglasses Get Dirtier, Faster
Running sunglasses deal with a specific cocktail of contaminants. Sweat, dust, sunscreen, rain, all of it accumulates on lenses within a single session. Regular eyewear collects fingerprints and the occasional smudge. Running eyewear collects salt residue baked on by sun exposure, sunscreen oils pressed into the nose pads, and fine grit kicked up from trails or roads.
This build-up is why generic cleaning advice falls short. A quick breath-and-wipe might work for reading glasses you wore at a desk. Running sunglasses that have been through 10 kilometres of summer heat need an actual process.
What Cleaning Sprays Actually Do to Your Coatings
Performance running sunglasses carry multiple coating layers: polarised, photochromic, AR-coated, UV400, hydrophobic, and oleophobic. Each one serves a purpose. Each one is vulnerable to the wrong solvent.
The problem is isopropyl alcohol. IPA is the primary active ingredient in most off-the-shelf lens cleaning sprays. Short-term, it cuts through oils and evaporates cleanly. Long-term, repeated use on coated lenses causes the coating layers to break down gradually. The same applies to alcohol-based hand sanitisers and alcohol wipes, which can damage the specialist materials and lens coatings on your sunglasses.
The alternative exists. Alcohol-free lens cleaners built on a deionised water base with a biodegradable non-ionic surfactant and no isopropyl alcohol, no ammonia, and no harsh solvents clean just as effectively without degrading coatings. Re.'s After the Run Lens Cleaning Kit is designed around this formula.
What Never to Use on Your Lenses
Before the cleaning steps, the full list of things that should never touch your lenses:
Cloths and wipes that scratch:
- Your shirt. The hem has been exposed to dust and pollen, and the lenses themselves carry dirt that scratches and further smudges glasses during wiping.
- Paper towels, tissues, and napkins. These are wood pulp in essence, highly abrasive, and many generate dust that stays on the lens.
- A dry microfiber cloth on its own. Even clean microfiber needs some form of liquid before wiping. Cleaning glasses when they are dry spreads debris across the lenses and frame rather than removing it.
Solutions that degrade coatings:
- Vinegar, bleach, ammonia, and window or glass cleaners (including Windex). These strip lens coatings, and their fumes can irritate the delicate tissues of your eyes.
- Alcohol wipes and hand sanitiser.
- Lemon or lime-scented dish soaps. Citric acid in these soaps contains salt, which can damage lenses and their coatings.
- Hot water, which can damage polarised and specialty lens coatings.
- Saltwater, which is abrasive and caustic enough to scratch lenses.
- Hard water. If your home has hard water, use distilled water for cleaning.
How to Clean Sunglasses: Step by Step
1. Wash your hands first. Oils and grit on your fingers transfer straight to the lens.
2. Rinse under lukewarm running water. This removes dust and debris that could potentially scratch the lenses during the cleaning process. If your sunglasses have been dropped in sand or dirt, hold them under running water before touching the lenses. Rubbing sand off dry will grind it straight into the coating.
3. Clean the frame before the lenses. Oils, dirt, makeup, and sunscreen concentrate on nose rests and frame contact points. If you start with the lenses, you risk smearing all of that across the optics.
4. Apply one drop of mild dish soap. Use soap without lotion or other additives. One drop is enough. Gently massage the lenses between your fingertips with soapy water until the smudges lift.
5. Use a soft toothbrush on hard-to-reach areas. A soft bristle brush or old toothbrush works for nose pads, vents, and hinges where grime builds up.
6. Rinse thoroughly. Leftover soap residue causes streaks and smudges on the lens when it dries, which can obscure your vision.
7. Dry with a clean microfiber cloth or air dry. A gentle circular motion with the microfiber. No paper, no shirt, no towel.
That is the full process. Two minutes, no specialist equipment beyond a microfiber cloth and basic soap.
Keeping Coatings Intact Between Cleans
Cleaning properly once is good. Maintaining the habit is what actually extends lens life.
Clean daily. Daily cleaning prevents serious build-up. Either before you leave the house or before bed, rinse and wipe. It takes less time than lacing your shoes.
Wash your microfiber cloth weekly. A dirty cloth defeats the purpose. Wash microfiber cloths each week, and do not use dryer sheets or fabric softener when you do. They leave a residue that transfers straight to the lens.
Carry alcohol-free wipes for on-the-go cleaning. Post-run or mid-race, a pre-moistened alcohol-free lens wipe handles sweat and sunscreen without the coating damage of an IPA-based alternative.
Store in a case. Loose sunglasses in a bag or on a dashboard collect scratches. Leaving sunglasses in a hot car can warp frames and damage lens coatings.
What Coatings Are You Protecting?
If you are running in performance sunglasses, you are likely running in multiple coatings without thinking about them. Polarised lenses reduce glare from roads and water. Photochromic coatings adjust tint as light changes. AR coatings cut internal reflections. Hydrophobic layers repel water and sweat. Each of these is a thin film applied to the lens surface, and each reacts badly to alcohol, ammonia, or abrasive contact.
Understanding what sits on your lens explains why a $3 spray bottle from a petrol station is a false economy. The lens itself might be fine. The coatings you paid for are not. For a deeper look at how these lens technologies work, see Re.'s lens technology page.
Frequently Asked Questions
Can I use Windex to clean my sunglasses?
No. Windex and other window cleaners contain harsh properties that can damage lenses and strip coatings. Use lukewarm water with a drop of mild dish soap, or an alcohol-free lens cleaner.
Is it okay to clean sunglasses with just a microfiber cloth?
Only if the cloth is wet. A dry microfiber cloth needs some form of liquid before wiping, because dry cleaning spreads debris rather than removing it. Dampen the cloth or rinse the lenses under water first.
How often should I clean my running sunglasses?
Daily cleaning prevents serious build-up. After every run is ideal. At minimum, rinse and wipe once a day if you have worn them.
Will alcohol wipes ruin my sunglasses?
Over time, yes. Alcohol wipes can damage specialist materials and lens coatings. A single use will not destroy the lens, but repeated exposure breaks down AR, polarised, and hydrophobic layers.
Tim Golubev
Founder, Re. (Re Your Run)
Tim built Re. after years of running in sunglasses that bounced, fogged, and ended up on his forehead. After discovering the UV damage that builds up without eye protection (even on cloudy days) and hearing the same frustrations from hundreds of other runners, he decided it was a problem worth fixing properly. With a background in Product across multiple industries, he approached it like any product problem: figure out what's broken, then build something that actually fixes it. He runs daily, co-founded Rose Bay Run Club, and Re. is his attempt to make one less thing that gets in the way of a good run.
