FRANKLIN, Mass., May 17 -- Thermo Vision Corp. has signed an agreement to acquire the assets of the non-telecommunications optical filter business of Optical Corporation of America (OCA), a wholly owned subsidiary of Corning Incorporated, for $4.0 million. The acquisition will not become effective until July 5, 1999, in order to allow time for the relocation of OCA's equipment and personnel from Marlborough, Mass., to Thermo Vision's Corion division in Franklin, Mass.