This amendatory Act of 1991 is intended to clarify and restate the provisions of this Article 13 and to make certain substantive changes. This amendatory Act shall not be applied to deprive any person of eligibility for an annuity or benefit, to reduce the annuity or benefit, or to deprive a person of any right to which that person would have been entitled prior to the effective date of this amendatory Act of 1991, if the person from whose employment the annuity, benefit or right derives was an employee prior to that date.
40 ILCS 5/13-102