Leslie Winkle, PhD (portrayed by Sara Gilbert ; main: season 2; recurring: season 1; guest: seasons 3 and 9) is an experimental physicist who shares her lab with Leonard. In appearance, she is essentially Leonard's female counterpart, equipped with black-framed glasses and sweat jackets. She suffers from lazy eye. She is one of Sheldon's archenemies due to their conflicting scientific ideas and takes every opportunity to insult Sheldon for mistreating her.