Any person licensed to practice the profession of optometry in this State who is serving in the armed forces of the United States in time of war or preparation for war during any national emergency shall not thereby forfeit his current license or registration. Any such person who has paid an annual renewal registration fee shall be refunded that portion of such annual renewal fee for the time that he has served in the armed forces of the nation. Any such person, upon presentation of his discharge from such service within one year from the date thereof and upon payment of the fee prescribed by law for the portion of the current renewal period only, shall be entitled to a renewal of his license or registration as though such renewal had been made prior to the expiration of his last preceding renewal and as though all intermediate renewal fees had been paid.