Section 73K. Any person entering the employ of a physician, optometrist, licensed dispensing optician as an apprentice for the purpose of obtaining the experience and training referred to in section seventy-three E, may make written application for certification as an apprentice with the board. Such application shall be made upon a form prescribed by the board and shall be accompanied by a certificate of the employer, verifying the statements made by the applicant. The applicant shall pay a filing fee to be determined annually by the commissioner of administration under the provision of section three B of chapter seven with such application. The board shall, upon approval of such application, issue to the applicant an apprentice's certificate, and thereupon the computation of any period of training and experience referred to in section seventy-three E shall begin. Any person who may have served part of his apprenticeship in any state or country not requiring such certification shall be obliged to give proof of such service satisfactory to the board. Time spent as an apprentice in the employ of a dispensing optician or a registered physician or optometrist prior to January first, nineteen hundred and fifty-six, shall be credited to the apprentice at such time of certification upon satisfactory proof of such service furnished to the board. A certified apprentice may perform any of the acts set forth in section seventy-three C under the personal supervision of a licensed dispensing optician, optometrist or physician.