Q:

Ingredients for cleaning optical elements

I have recently purchased a cleaning solution for precision optics which has the following ingredients (amounts were not specified):

Ethyl Alcohol
Methylethylketon
Aqua
Diethyl Ether
Isopropyl

Typically reagent grade isopropyl alcohol alone is used for cleaning optical elements. So, does the mixture above provide any advantages over using pure isopropyl? (Possible advantages may include a faster dry time, better removal of oils/smudges, and less toxicity)
Any explanations would be greatly appreciated.

A:

It might possibly be intended to dissolve an adherent organic film, such as that left by evaporation of plasticizers from foam packaging.
However, it also might well partially dissolve paints and cements used in the lens assembly, leaving yet harder-to-remove dirt on the lens. Unless you have a specific need for those solvents, use distilled water and/or isopropanol, according to B&H.

