Edmund Optics, of Barrington, N.J., announced it appointed Ruth Stevens, an adjunct professor of marketing at Columbia Business School, to its board of directors. Stevens is president of eMarketing Strategy, based in New York City. She was recently chief marketing officer at two Internet startup companies in New York and previously had direct-marketing responsiblities at IBM, Ziff-Davis and Time Warner.    . . .    Microvision, a maker of light-scanning technologies for display and imaging, was awarded a $1.2 million subcontract from General Dynamics C4 Systems to supply 165 Nomad helmet-mounted display systems as part of the initial phase of the US Army's "mounted warrior" soldier system. The Army recently awarded General Dynamics a contract to develop and equip combat vehicle crews with advanced situational awareness capability, including combat helmets and wireless voice communications. Microvision said it expects to ship the units for testing, initially in Stryker armored vehicles, in the next few months.    . . .    Maureen L. Lamb was appointed CFO of Photon Dynamics Inc., a supplier of integrated yield-management systems for the flat-panel display market. Lamb, whose appointment is effective May 31, is vice president of finance at KLA-Tencor, a manufacturer of test and measurement equipment for the semiconductor industry. Lamb will replace Richard Okumoto, the current CFO of Photon Dynamics, who is stepping down for health reasons. He will remain with the company to assist Lamb through Dec. 1.