Robbie had been busy sulking behind those glasses at the threat from his wife to go Mommy on him, then Zelda's question drew his attention. "Hm? Oh, no, no. My vision simply started to deteriorate over the years, and I decided to be creative. One hundred years has a lot of time to get bored during, I'm afraid, even when you're devoted to research. The mind needs a break now and again, and I needed some form of corrective lensing. I saw an opportunity to experiment."