Nothing in this chapter shall be construed to apply to:
(1) physicians and surgeons authorized to practice under the laws of the state of Montana;
(2) a person employed in the office of and acting under the direct personal supervision of a physician or surgeon;
(3) an optician performing the required mechanical work under an order or prescription signed by a duly licensed physician, surgeon, or optometrist;
(4) commissioned officers of the armed forces of the United States performing functions of this chapter in the line of their regular duty; or
(5) persons who sell spectacles or eyeglasses without attempting to traffic upon assumed skill in adapting them to the eye.