Cleaning Optical Mirrors vs. Lenses – Key Differences


Optical mirrors and lenses can get contaminated in many ways. The contamination can be minimized by returning the optics to their cases after use. Covering them for protection from the outside environment can also keep them clean for longer. Unfortunately, even with all these precautions, these items will eventually accumulate stains, dust, and other forms of contamination.

The most recommended procedures for cleaning both optical mirrors and lenses are largely same. The first step in cleaning optics is blowing the dirt and dust off the optical mirror or lens using pressurized air. Then, the drag methods allow you to slowly move a wet lens paper across the optical component surface. Most professionals who use these items know the pitfalls to be avoided when cleaning them. However, some key differences make optical mirrors more susceptible to damage during the cleaning process.

Here are the three important points to remember when cleaning optical mirrors.

Clean, protected mirrors only

A bare metallic coating is very delicate and can easily scratch when exposed to regular cleaning procedures. Therefore, only optical mirrors with improved or protected surface coatings should be cleaned using these methods. In the event that you need to clean an unprotected mirror surface, consider using compressed air only instead of moisturized paper.

Never use dry lens paper

One of the most effective ways of cleaning both optical mirrors and lenses is the use of lint-free lens paper that has been moistened using a recommended cleaning solution. Using a dry lens paper can scratch the mirrors by dry cleaning materials. Thus, always be sure to moisten the cleaning paper with the right chemical solution before cleaning the mirror. This will help in keeping the optical mirrors in good shape for a long time.

Always use the optimal reagent

When choosing chemicals for cleaning optical mirrors and lenses, the choices are majorly 97 percent to 99 percent methanol isopropyl alcohol, mild detergent, or acetone. Acetone and reagent-grade alcohol are the most commonly used chemicals to clean mirror surfaces. Alcohol is often preferred because it evaporates faster than acetone, thereby avoiding spots and streaks.

After buying an optical equipment, practicing proper care can maintain its original quality for a long time. Choosing the right cleaning product and the most effective cleaning method is as crucial as cleaning the product itself. Improper cleaning can result in damages to polished surfaces or even specialized coatings that are used on optic mirrors and lenses, degrading the performance in various applications.

In most cases, lenses are cleaned using reagent-grade alcohol or acetone or a special lens cleaning solution. When cleaning the lenses, you can apply slight pressure in the center and work outward, to pull off any form of dirt instead of spreading it on the lens’ surface. On the other hand, you should carefully clean mirrors. It’s recommended to use compressed air to blow off the dirt instead of wiping the mirror surface. After blowing, you can use the drag to eliminate fingerprints and other contaminants from the mirror surface.