With cleaning glass it really is a case of "it depends" as to what you use. In general most optical glass will have a coating of one or more antireflective or filtering material on the surface, and these can be affected by many things, water included. Bare glass not so much, but those coatings are proprietary per lens manufacturer, and vary a lot. So, best is to start with the things that are least likely to damage, like a clean lint free absolutely dry cloth used to pat the surface ( not a wipe, as this will leave scratches) clean of dust. then you can use distilled water, using another clean microfibre cloth as a wash. Alcohol ( 20% ethanol in water, also called 40 proof cane spirit, not Vodka or anything else, only the clear tasteless stuff ( Mainstay, Mainstay as a brand here) from a nip bottle still sealed) is the next, as it leaves no film, as the base ethanol is 99.6% ultra pure, and the water for blending is first DI and then RO filtered. This may affect some AR films, so the low alcohol content is good.
Do not use any stronger solvents, as many AR films are organic acids that dissolve or react with them. With many lenses you will also need to do the most horrid thing you can think of, and dismantle the lens out of the housing, so that you can take the lens and use a very destructive cleaning on it to kill fungus that has colonised the AR coating and is using it as food. With that your only choice is to strip the layer off, or kill the fungus with either bleach or peroxide, which can further damage the film. When doing the fungal kill, take the housing ( remove all the glass and other parts) and put the aluminium parts in a glass high temperature container, and boil on a stove to kill the spores in the pores of the metal. Plastic you have to chance the peroxide, and with compound lenses you also have a risk of the optical epoxy that glues them together being attacked, so you will need to contact the manufacturer as to which one they used, and if you can buy a lens off them if available. Otherwise you will have to dissolve the epoxy, split the lenses and clean them ( AR coating is pretty much going to be toast here) in strong solvents like MEK, and use some optically clear UV cure resin to put the kit back together. Will never be the same, but better to have at least clear glass as opposed to a growing fungal film that eats the other lenses.