Honnestly, everyone has a different opinion, but his eyes seem normal sized, and are fine. there is no such thing as universally perfect eyes, everyone has a different point of view, ex: one person could be a big fan of deep blue eyes and another could be a fan of deep browns.
His eyes are average sized. Not small and not big. When I look at him I'm not thinking about his eyes, that's for sure! He does have nice eyes now that you think of it, but they aren't his standout feature, that man just looks good overall. His smile and body is his best feature.
Listen I am not gay, but Ronaldo is possibly one of the best looking guys in the world. I work out every day at least once to try and get a body like him, and you're talking about him having small eyes? Really bro, you're just trying to find an imperfection in someone that's easily an 11 out of 10.