Cal. Bus. & Prof. Code § 690

(a) Except as provided in Section 4601 of the Labor Code and Section 2627 of the Unemployment Insurance Code, neither the administrators, agents, or employees of any program supported, in whole or in part, by funds of the State of California, nor any state agency, county, or city of the State of California, nor any officer, employee, agent, or governing board of a state agency, county, or city in the performance of its, his, or her duty, duties, function, or functions, shall prohibit any person, who is entitled to vision care that may be rendered by either an optometrist or a physician and surgeon within the scope of his or her license, from selecting a duly licensed member of either profession to render the service, provided the member has not been removed or suspended from participation in the program for cause.
(b) Whenever any person has engaged, or is about to engage, in any acts or practices that constitute, or will constitute, a violation of this section, the superior court in and for the county wherein the acts or practices take place, or are about to take place, may issue an injunction, or other appropriate order, restraining the conduct on application of the Attorney General, the district attorney of the county, or any person aggrieved.
For purposes of this subdivision, “person aggrieved” means the person who seeks the particular medical or optometric services mentioned in this section, or the holder of any certificate who is discriminated against in violation of this section.
(c) Nothing contained in this section shall prohibit any agency operating a program of services, including, but not limited to, a program established pursuant to Article 5 (commencing with Section 123800) of Chapter 3 of Part 2 of Division 106 of the Health and Safety Code, from preparing lists of healing arts licensees and requiring patients to select a licensee on the list as a condition to payment by the program for the services, except that if the lists are established and a particular service may be performed by either a physician and surgeon or an optometrist the list shall contain a sufficient number of licensees so as to assure the patients an adequate choice.