Dean Cain Good Genes or Good Docs?

6/17/2013 3:30 AM PDT BY TMZ STAFF
0612_dean_cain_superman_genesDean Cain is a Superman.

Here's the 26-year-old "Lois and Clark" actor back in 1993 (left) -- and twenty years later, the 46-year-old "Ripley's Believe It or Not" host at the Philly Comic-con last month (right).

Dude looks great -- question is ...