grease on Canon 10x30 IS eyepiece

Folks, I bought a used Canon 10x30 IS and have been very pleased with it.
However I notice that there is some oily substance smudging the eyepiece
and I traced it back to something that looks like grease under the rubber
eyecups. I'm puzzled as to why there is grease under the eyecups. I wonder
if that was not the doing of the previous owner rather than Canon. This material
seems hard to get completely off the lens, I can still see smudges. Can anyone
confirm whether a newly bought Canon IS binoc would have this grease and how
to clean it?

Thanks
Ashok

Ashok,

That seems very odd. I have the 12x36 IS IIs here, and my father-in-law has the 10x30s. I haven't noticed any grease on either. Also, mine focus by moving the objective lenses, and I am fairly sure it is the same with all the versions, including the 10x30. Because of this I don't see any need for any sort of grease near the eyepieces.

In cleaning optics I've sometimes found that the choice of solvent is important. Some things come off with lens cleaner, some with isopropyl alcohol, and some with a mild, diluted detergent. A little saliva on a fingertip can get some things that don't respond to other methods.

I don't know what to recommend if it really is grease, and you should probably get it off the glass and out from under the rubber eyecups. Perhaps others will know of a good degreaser.

Clear skies, Alan