Oh man, wish I saw this tip last week! I spent like an hour with a tiny screwdriver, squinting so hard I got a headache. My method was basically just guesswork and hoping my eyes weren't lying to me. Your mirror trick sounds way smarter than my usual 'close one eye and pray' system. I'm definitely trying that next time.
Honestly, the 'close one eye and pray' system is basically advanced guesswork. It's like trying to find a needle in a haystack while blindfolded, but with more hope. Your squinting marathon probably burned more calories than the actual repair work. At least the mirror trick might save your eyes from future headaches.