TL;DR
Polarized lenses carry a light-filtering layer that alcohol, ammonia, and heat can ruin, and sunglasses collect three things regular glasses do not: sunscreen, salt, and beach grit. Rinse them under lukewarm running water first, wash with a drop of lotion-free dish soap, rinse again, and dry with a clean microfiber cloth. Never leave them baking in a car.
What makes polarized lenses different
A polarized lens contains a filter that blocks light waves oriented in one direction, which is what cuts glare off water, snow, and road surfaces.
In most lenses that filter is a thin film either laminated between layers of lens material or applied as a coating near the surface. Either way it is chemically vulnerable in ways plain tinted plastic is not.
Solvents can attack the film or the adhesive holding it, which shows up as bubbling, a rainbow sheen, delamination at the edges, or a patchy loss of the glare-cutting effect. Heat does the same thing more slowly.
On top of that, most sunglasses also carry the standard coatings -- anti-reflective, scratch-resistant, ultraviolet, sometimes a mirror finish on the outside. Mirror coatings are the most fragile surface on the whole pair.
How do you clean polarized sunglasses?
Rinse them under lukewarm running water to remove grit and salt, apply one small drop of lotion-free dish soap to each lens, rub gently with clean fingertips, rinse thoroughly, and dry with a clean microfiber cloth. Skip alcohol, ammonia, glass cleaner, and paper towels entirely.
The three things sunglasses collect
Sunscreen. This is the big one. Sunscreen transfers from your face and hands onto lenses and frames, and some of its ingredients are aggressive toward plastics and coatings. It also leaves a stubborn haze that a dry wipe just spreads around. Wash it off the same day rather than letting it sit.
Salt. Ocean spray, and sweat during exercise, both leave salt crystals as they dry. Salt is hard and sharp at the microscopic scale, so wiping dry salt across a lens scratches it. Rinsing is not optional after a beach day.
Grit. Sand, trail dust, and road dust are mineral and harder than lens plastic. Same rule: float it off with water before anything touches the surface.
Insect repellent deserves a mention too. Some repellents dissolve plastics and finishes on contact, and it is easy to transfer from a hand to a frame. If any gets on a frame, wash it off immediately.
The general grit-first principle is the same one behind how to clean eyeglass lenses without scratching, and it comes up across the whole category in cleaning the personal items you use every day.
The wash, step by step
1. Rinse under lukewarm running water. Not hot. Heat softens lens plastic and stresses laminated films.
2. One drop of plain dish soap on each lens. Lotion-free. Lotion-added soaps leave a film.
3. Rub gently with fingertips. Both lens faces, the frame front, the temple arms, the nose pads, and the hinges.
4. Pay attention to where the lens meets the frame. Sunscreen and skin oil collect in that groove and slowly work under the edge of a lens.
5. Rinse everything thoroughly.
6. Shake off the water and blot dry with clean microfiber. Do not scrub. Blot, then wipe lightly in one direction.
If the cloth has been in a bag or a pocket, wash it first or use a different one. A gritty cloth undoes the whole exercise.
Why did my polarized lenses go rainbow or cloudy?
That pattern usually means the polarizing film or a surface coating has started to separate, most often from heat, solvents such as alcohol or ammonia, or age. It is permanent. The most common cause is leaving sunglasses on a dashboard, where interior temperatures climb far higher than the outside air.
Heat is the quiet killer
A closed car in summer routinely reaches temperatures well above what lens laminates and frame adhesives tolerate.
That heat warps frames, loosens the glue holding lenses in, and accelerates the delamination that produces the rainbow sheen. Cheap and expensive sunglasses both fail this way.
Do not leave them on a dashboard, in a glove box on a hot day, or on a beach towel in direct sun. Do not wear them on your head at a pool for hours, where sunscreen and chlorine both work on them.
Store them in a hard case. Lens down on a table is how the outer surface gets scratched, and a mirror finish will show every mark.
Electronics in a bathroom or a beach bag face a similar heat-and-moisture problem, which is why how to clean hearing aids without water damage treats drying and storage as the main event.
Source: American Academy of Ophthalmology consumer guidance on eyewear care
Cleaning frames without wrecking them
Frame material decides the method.
Acetate and other plastics tolerate soap and lukewarm water fine. Dry them promptly.
Metal frames wash the same way, but check the small screws afterward, since they work loose over time and a jeweler's screwdriver takes ten seconds.
Wooden and bamboo frames should be wiped with a barely damp cloth, never soaked, and never left wet.
Rubberized nose pads and temple grips get slick with sunscreen. A soft toothbrush kept for the purpose, used gently with soapy water and away from the lens, cleans them properly.
If the whole pair lives in a bag with makeup and sunscreen, the bag is part of the problem -- see how to clean a makeup bag inside and out.
What to do after a beach or pool day
Rinse them with fresh water before the salt or chlorine dries. That single step prevents most of the long-term damage.
Then wash properly with soap and water, dry with microfiber, and let the frame air out for a few minutes before it goes back in a case. Sealing a damp pair in a case leaves the hinges wet.
Sunglasses that have taken a swim in salt water need a longer freshwater rinse, including the hinges, where salt crystallizes and drives corrosion in metal parts.
FAQ
Can you use rubbing alcohol on polarized sunglasses?
No. Alcohol can attack the polarizing film, the adhesives that hold laminated layers together, and any anti-reflective or mirror coating on the surface. The damage looks like clouding, a rainbow sheen, or peeling at the edges, and it is permanent. Use mild dish soap and lukewarm water instead.
How do you get sunscreen off sunglasses?
Rinse under lukewarm running water, then wash with a small drop of lotion-free dish soap, rubbing gently with your fingertips across the lenses, frame, and nose pads. Rinse thoroughly and dry with clean microfiber. Wash it off the same day, since some sunscreen ingredients degrade plastics and coatings over time.
Why do polarized lenses get a rainbow pattern?
That sheen is usually the polarizing film or a coating starting to delaminate, most often caused by heat, solvents, or age. Leaving sunglasses in a hot car is the single most common cause. Once it appears it cannot be cleaned away, and the lenses have to be replaced.
Can you put sunglasses in hot water?
No. Hot water softens lens plastic, stresses laminated polarizing films, and can loosen the adhesive holding lenses into frames. Lukewarm water is warm enough to lift sunscreen and skin oil with a little dish soap, and it will not put the lenses at risk.
Is it okay to clean sunglasses with a shirt?
It is one of the fastest ways to scratch them. Clothing holds mineral dust, and wiping dry dust across a lens grinds it into the coating. If the lenses are gritty, rinse them. If they are only smudged, use a clean microfiber cloth and a light touch.
How should you store sunglasses?
In a hard case, out of direct sun and away from heat. A dashboard, a glove box on a hot day, or a beach towel in full sun all reach temperatures that damage laminates and frame adhesives. Setting them lens down on a table is how the outer surface gets scratched.
Sunglasses take two minutes. The house they come home to takes longer. If you would rather hand that off, get a quote or read more about house cleaning services.