My oculus quest 1 oled display gives no black smears and even so a little smear I can tolerate. Now what lens could I buy to make this work?
FOV reduction help nausea, but in your post you were talking about how screen door effect reducing nausea, which I can't see any evidence for.
Either way, slapping a smartwatch to your eye is a very early 2010s thing to do and will maybe give you a bit of novelty for a minute but is not something that has any real use in the current world of real HMDs.
I'm enthusiastic about something you consider "a very early 2010 thing to do" and not having any real use case in the "current world of real HMD's". Like you I live in the current world of real HMD's. My use case is enjoying playing quake on the smallest waterproof device possible. Q1 on the apple watch can be considered a novelty, yes, but I would like to take it as far as possible, because I like retro and repurposing and I like the size of the apple watch compared to a quest.
Of course, QuakeVR on Q2 exists, Apple HMD's are on the radar and I could link my android phone with a lightweight HMD and play quake that way. Why bother? Good question