Seems to me that from a self-defense perspective, one should practice in the mode that they would most likely be in. At home, I seldom wear glasses. In a "situation", glasses can easily be left behind, lost, or knocked off. At the range, I practice without prescription glasses. That gives me a slightly fuzzy front sight and a much-fuzzy target picture. I figure that's the mode I will most likely be in most ofthe time.
I gave up on winning any markmanship competitions years ago.