Every practitioner of optometry shall post and keep conspicuously displayed his or her license in the office wherein he or she practices. If an optometrist practices at several locations in the state, the optometrist shall display his or her license number and name in a manner that can be easily recognized by his or her patients. Each association of persons who engage in the practice of optometry under the name of a partnership, association, or any other title shall cause to be displayed and kept in a conspicuous place at the entrance of its place of business the name of each person engaged or employed in said partnership or association in the practice of optometry.