Apparatus for identifying a person who wishes to receive information, where identifying information for each of a plurality of registered individuals is stored in a database, calls for capturing images of an individual requesting information, and determining whether this individual is the same as one of the registered individuals. The stored identifying information includes images of a unique, observable biologic identifier on a body portion of each registered individual. The specificity of the identification process is enhanced by storing registered examples of altered biological information in the database, by allowing the information provider to induce an alteration in a biologic identifier of a requesting person at the time of the request, and by comparing the altered requesting person information to stored information. Further identification enhancement is obtained by rapidly altering the visual environment of the requesting person, and by providing the requested information to the retina of the requesting person.