My control variables are
1. water hardness level, as I live in Florida, and I lodged at a Ritz Carlton also in Florida. I'm not, in any way, affiliated with any corporation herein.
2. my eyeglasses with $700 USD Nikon SeeMax Ultimate lenses.
3. my cleaning method
4. and my Nikon micro-fiber lens cleaning cloth.
When I lodged at the Ritz Carlton hotel, I used their liquid hand wash to dab my eyeglasses.
But even when I used different bottles of this hand wash, after rinsing with the Ritz's tap water, my eyeglasses remain smudged. I didn't take the images below, but they resemble my smudges.
When I got home, I daubed some of my Method Gel Hand Soap Refill, Sweet Water
on my Nikon lenses as usual. Then rinsing with my home's tap water cleansed the smudges.
Therefore Ritz Carlton's liquid hand wash appears to be the culprit for my smudges. But I never knew that some liquid hand washes can cause smudges?!!!?! What do you chemists think?
I'm not affiliated, or in any way connected with, any corporation named in this post.