85.64  Limitation of benefits.
  If an employee who has previously lost, or lost the use of, one hand, one arm, one foot, one leg, or one eye, becomes permanently disabled by a compensable injury which has resulted in the loss of or loss of use of another such member or organ, the employer shall be liable only for the degree of disability which would have resulted from the latter injury if there had been no preexisting disability. In addition to such compensation, and after the expiration of the full period provided by law for the payments thereof by the employer, the employee shall be paid out of the “Second Injury Fund” created by this division the remainder of such compensation as would be payable for the degree of permanent disability involved after first deducting from such remainder the compensable value of the previously lost member or organ.
  Any benefits received by any such employee, or to which the employee may be entitled, by reason of such increased disability from any state or federal fund or agency, to which said employee has not directly contributed, shall be regarded as a credit to any award made against said second injury fund as aforesaid.
[C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §85.64]