(1)    No person shall practice optometry within the meaning of this chapter without a license to do so and a valid certificate of registration issued by the examining board, except that a dispensing optician need not be so licensed for the practice of optical dispensing.

   (2)   This section shall not apply to physicians and surgeons duly licensed as such in Wisconsin nor shall this section apply to the sale of spectacles containing simple lenses of a plus power only at an established place of business incidental to other business conducted therein, without advertising other than price marking on the spectacles, if no attempt is made to test the eyes. The term “simple lens” shall not include bifocals.

   (3)   This section does not apply to a person who practices optometry under the supervision of an optometrist licensed under this chapter. The examining board shall promulgate rules specifying the conditions for supervision required under this subsection.