I was diagnosed Stage IV in June 2015. Did Opdivo/Yervoy combo and then moved to Keytruda. I too now have floaters in my eye. As people in their early 30s (33 when diagnosed) don't tend to get floaters, I and my doctors/nurses do think it was a side effect. They seem to have stabilized since moving to the Keytruda. Besides that and some vitiligo/hair whitening I'm doing great.