Section 55(2) in The Employees' State Insurance Act, 1948
(2)Any assessment of the extent of the disablement resulting from the relevant employment injury may also be reviewed by a medical board, if it is satisfied that since the making of the assessment there has been a substantial and unforeseen aggravation of the results of the relevant injury:Provided that an assessment shall not be reviewed under this sub-section unless the medical board is of opinion that having regard to the period taken into account by the assessment and the probable duration of the aggravation aforesaid, substantial injustice will be done by not reviewing it.
