California Code, Business and Professions Code - BPC § 3040

(a) It is unlawful for a person to engage in the practice of optometry or to advertise or hold himself or herself out as an optometrist without a valid, unrevoked California optometrist license. The practice of optometry includes the performing or controlling of any acts set forth in Section 3041.

(b) In any prosecution for a violation of this section, the use of test cards, test lenses, or of trial frames is prima facie evidence of the practice of optometry.