Curiosity: I believe it’s a Machlokes Haposkim and I was told that the majority hold it has to be identifiable as a bug, not just a speck. The issue is that there are things that would have been identifiable as a bug before you washed and killed them but now aren’t. Those may not be eaten.
Choc: Unless I’m misinformed, the bugs in broccoli melt under high heat. There’s also a Sfek Sfeka to rely on if they don’t.
Rob: Glasses are necessary because the naked eye is determined by the average person’s vision. We assume that that means 20/20 (even though it probably means something closer to 20/40, especially for Jews).