John Hancock has become president of Gerber Coburn Optical, replacing Shawn Harrington who was recently appointed as CEO of the US firm and chief financial officer of its parent company, Gerber Scientific. A former executive of American Optical and Omega Optical, Hancock has held several sales and marketing positions within Coburn Optical before and after its 1998 acquisition by Gerber. Also, Todd Rhodes has been promoted to the post of director of product management. Separately, George Gentile has been named chairman of Gerber Scientific, and Marc Giles has become president and CEO. They replace Michael Cheshire, who has resigned as chairman and CEO of the American group.