Nikon Corp. of Japan has promoted Geoff Wild and Gil Varnell to CEO of Nikon Precision Inc. and Nikon Research Corp. of America, respectively. Both companies are based in Belmont, Calif.   . . .    StockerYale Inc. has received an $800,000 order for custom designed, light-emitting diode illuminators from one of its newest European OEM customers. The company's facility in Cork, Ireland, will manufacture and ship all units by the end of 2003; additional orders are expected.