dear friend ,
this is a case of OPTIC NEURITIS
.but details of the child is not sufficient .your child may be suffering from MUMPS
which can predispose the person after 1-2 weeks for optic neuritis .person will presents as severe vision loss
in both eyes and other features of meningiencephalitis .TREATMENT :no teatment required in majority of cases because spontaneous visual recovery is good but in some cases intravenous corticosteroid is required .