Recently there was an exchange on the Confocal Listserver about the proper method for cleaning objective lenses. Some suggestions were useful and were some fraught with danger. This article is adapted from my reply to the list.

There are only three hard and fast rules about lens cleaning:

1. 1) Never “dry” clean a lens.

2. 2) Use a solvent or dispersant that is likely to remove whatever is on the lens.

3. 3) Use the best quality lens tissue available.

The most likely source of damage to glass surfaces and fine optical coatings is abrasion. The particles that cause the abrasion are the particles on the objective lens surface and the particles in whatever is used to wipe the lens.