57.985.  Deferred normal annuity — forfeiture of rights in fund — creditable service restored, when — absence counted as membership service, when — ineligible for benefits while in public employment. — 1.  Upon termination of employment, any member with eight or more years of creditable service shall be entitled to a deferred normal annuity, payable at age fifty-five with twelve or more years of creditable service, and payable at age sixty-two with less than twelve years of creditable service.  Any member with less than eight years of creditable service shall forfeit all rights in the fund, including the member's accrued creditable service as of the date of the member's termination of employment.

  2.  A former member who has forfeited creditable service may have the creditable service restored by again becoming an employee and completing four years of continuous membership service.

  3.  Absences for sickness or injury of less than twelve months shall be counted as membership service.

  4.  No person shall be eligible to receive any benefits under the provisions of sections 57.949 to 57.997 except section 57.980 while serving as sheriff in the state of Missouri.

  5.  Any present or future members of the retirement system upon their application for membership for benefits under the current law who retired prior to August 13, 1986, are hereby appointed and employed as special consultants by the retirement system for the remainder of the member's life, and shall be available to give opinions, written or orally, as the board from time to time might request, and for such services shall be eligible for all the benefits that the present or future retirees are entitled to receive.