Fungus can permanently damage lens coatings, so the coating may already have been etched before cleaning. Very strong alcohol is not ideal; if you use alcohol, a lower concentration such as 70–90% is generally safer than 98%.

For fungus specifically, one commonly recommended approach is to remove the affected elements and treat them with an aqueous hydrogen peroxide + ammonia solution, then rinse with distilled water and dry with a truly lint-free cloth or paper. Expect to clean more than once to remove residue and smudges.

A few practical tips:

• Use genuinely lint- and dust-free wipes for drying.
• Make sure there are no metal, glass, or grit particles on the element before wiping, or you can scratch it.
• Handle elements carefully; tools like contact lens lifters can help, though they may leave residue that needs another cleaning pass.
• Alcohol-based eyeglass wipes can be acceptable for less critical cleanup, but avoid soap-based products.

If the coating is already etched by fungus, cleaning will not restore it.