The short answer: An ultrasonic cleaner is a small device that fills a tank with water and sends high-frequency sound waves through it. Those waves create millions of microscopic bubbles that collapse against every surface of an object — a process called cavitation — lifting off dirt, oil, and bacteria without anything physically touching it. It’s how opticians and jewelers have cleaned delicate items for decades.
How ultrasonic cleaning works
Inside the device, a component called a transducer vibrates at a frequency far above human hearing (around 40–42 kHz). Those vibrations pass through the water and create countless tiny bubbles. The bubbles grow and then collapse in an instant, releasing a small burst of energy right at the surface of whatever is in the tank.
Repeated millions of times per second, across every part of the object at once, this gently knocks dirt loose — even from cracks, seams, and hinges that a cloth or brush could never reach. Because the cleaning is done by the water and bubbles, nothing scrapes or rubs the surface.
Why that matters for glasses
Cleaning glasses by hand has two problems: a dry cloth scratches coated lenses, and no cloth can reach the frame, nose pads, and hinges where most oil and bacteria collect. Ultrasonic cleaning solves both. It reaches everywhere at once and never touches the lens, which makes it the safest method for coated eyewear. We compare the two directly in ultrasonic vs. microfiber.
What a cycle looks like
- Fill the tank with water and add a cleaning tablet (or a drop of mild soap).
- Place your glasses in the basket.
- Press start — the device runs for about three minutes and shuts off on its own.
- Remove and dry. The water is often visibly cloudy afterwards — that’s everything that was on your glasses.
Do you need special solution?
For glasses, plain water already works well, and a cleaning tablet boosts the result without harsh chemicals. Avoid pouring in alcohol or ammonia cleaners — they aren’t needed and can harm coatings. The cavitation does the work, not the chemistry.
Is it safe?
Yes, for items designed to handle it — glasses, jewelry, watch bands, and more. The key is using a device made for the job. Lensio is built for eyewear and tested on AR, HEV, and UV coatings, so it cleans deep without damaging the lens. (Curious what else fits in the tank? See what else you can clean in an ultrasonic cleaner.)
Frequently asked questions
What does “cavitation” mean? It’s the forming and collapsing of microscopic bubbles in the water. The collapse releases energy that lifts dirt off surfaces — the core of how ultrasonic cleaning works.
How long does an ultrasonic cleaning cycle take? For glasses, about three minutes per cycle.
Will it damage my glasses or coatings? No, when the device is made for eyewear. Nothing touches the lens, so it’s gentler than wiping.