I do think that the restriction is missing a "vision" in there somewhere to make it absolutely "clear" because yes, the restriction is obviously meant to apply to cyber- or bioware augmentations or replacements for your eyes.
Well of course it would only apply to eye augments, it doesn't make sense otherwise. My point was, you have to interpret the rule already, because otherwise it makes no freaking sense.
Which means you should also consider interpreting the other part of the sentence.
But anything implanted in your eyes would qualify as an "augmentation" for your eyes.
I also think that it is perfectly reasonable for other electronic vision enhancements to ruin the ability for Hawkeye to work because of what it does: Your eyes are really sharp and precise, so much so that you get a +1 on sight and treat everything as one step closer. If you're using a visual display of any sort that reproduces images rather than purely optical ones it cuts off that extra ability you have with your natural eyes.
Image link or smartlink don't reproduce the image though. They're an overlay that superimposes some additional information into your natural vision, and it doesn't matter if that's done through goggles, contact lenses or direct implant into your meat eyes. Why would this change how you see the rest of the world?
Vision magnification somehow has to reproduce the image though, as you're zooming in, there's no way around it, which is why I did say, I don't think those stack. Mostly for balancing reasons though, since reducing the range from Extreme to Medium is a +5 bonus, and that's crazy.
As for Vision Enhancement (the actual mod, not the category), this can take different forms. It could be that it replaces the image and makes everything sharper, but it's just equally conceivable that it simply highlights certain things here and there, drawing attention towards hard to spot things, etc, in which case I think it should totally stack. It's a bit of GM interpretation there.
As I said, take Low Light Vision as an example. Would Smartlink or Image Link take that away? No of course not. So why would "better eyesight" be taken away?