In this prospective study , a cohort of 91 eyes with congenital cataract and 25 eyes normal eyes from Wenzhou medical university was erolled.91 eyes with congenital cataract was after lensectomy and anterior vitrectomy as test group, 25 normal eyes as control group. The a- and b-wave and PhNR related parameters was evaluated.

Secondary IOL implantation in aphika children and lensectomy and anterior vitrectomy and primary IOL implantation in children with congenital cataract were both performed by the same surgeon(Z.Y.E).

electroretinography and photopic negative response are performed to each patient.The research was to evaluate the relationship between the best corrected visionn and the related parameters of a- and b-wave and PhNR .

Inclusion Criteria:

• phakic children diagnosed with congenital cataract who underwent secondary IOL implantation and children with congenital cataract who underwent lensectomy and anterior vitrectomy and primary IOL implantation

Exclusion Criteria:

• patients with mild cataracts do not require surgery

congenital cataract age from 1.5 years to 15 years who underwent cataract surgery at least 1 year