This episode's headline: Nicaragua: An Opposition View; Cutting Down Medical Costs; Cutting Out Glasses; Miraculous Mom. The guests include In Boston: ARTURO CRUZ, Nicaraguan Opposition Leader; In Atlanta: Dr. GEORGE WARING, Emory University; Reports from News Hour Correspondents: PETER GRAUMAN (KCET), in Los Angeles; GREG CHINTON (Visnews), in Chile; CHARLES KRAUSE, in Nicaragua; KWAME HOLMAN, in California; CHARLAYNE HUNTER-GAULT, in New York. Byline: In New York: ROBERT MacNEIL, Executive Editor; In Washington: JUDY WOODRUFF, Correspondent