In most episodes of The Big Bang Theory, Johnny Galecki (Leonard Hofstadter) wears glasses without lenses. This is probably true with Melissa Rauch (Bernadette Rostenkowski) and Mayim Bialik (Amy Farrah Fowler) as well, because it prevents glare.
Two of Galecki's former co-stars from Roseanne have had roles on the show: Sara Gilbert as Leslie Winkle and Laurie Metcalf as Mary Cooper.
The Big Bang Theory has been nominated for an Emmy, along with Jim Parsons (Sheldon Cooper), and Bialik. Find out if they win on September 23, 2012.