Sheer determination to go without glasses and force my eyes to focus. Then it eventually became too much effort (to the point of squinting to get a smaller aperature/larger depth of field or reading things at arms length, lol!) and near impossible with small print in dimly lit restaurants or anywhere dim. My ex-gf was office manager at an optometrist/opthamologist's office, she gave me my first pair of readers and I became a believer. Thankful I'm only at 1.25x since I started wearing them and have been holding steady there for many years.