(3) The presiding officer, on the application of any elector who is incapacitated, from any physical cause other than blindness, from voting in the manner provided by this Act, shall require the elector making such application to make oath in the form set out as Form 17 in Schedule 3 of his or her incapacity to vote without assistance, and shall thereafter assist such elector by marking his or her ballot paper in the manner directed by such elector in the presence of the poll clerk and of the sworn agents of the candidates and of no other person, and shall place such ballot in the ballot box.