A member of the national guard who has served faithfully therein for a period of not less than ten years, at least five years of which shall have been as a commissioned officer, at his or her own request, may be placed on the retired list with the highest rank held by him or her during such service; and if a commissioned officer who has not had the full length of service herein required, becomes permanently disabled to perform his or her duties, upon his or her own application, in the discretion of the commander in chief, he or she may be placed upon the retired list with the rank last held by him or her.