In this study, the investigators provide participants who had congenital cataract the multifocal contact lenses and bifocal spectacles in the purpose of seeking out a better way to make a definite diagnosis with high efficiency and accuracy, and report a prospective, randomized controlled study aiming at comparison of multifocal contact lenses and bifocal spectacles.

Children diagnosed as cataract without treatment were enrolled to a prospective, randomized controlled study. Patients were assigned to four groups: participants in group A wearing multifocal contact lenses a week and then bifocal spectacles a week;in Group B, the participants wearing bifocal spectacles a week and then multifocal contact lenses;in Group C, the participants wearing multifocal contact lenses four a year;in Group D, the participants wearing bifocal spectacles four a year. Investigators compare the acuity, refraction, contrast sensitivity and the results of questionnaire between A and B , C and D groups.

Inclusion Criteria:

• diagnosed as binocular cataract
• after the surgery of binocular intraocular lens implantation more than one month

Exclusion Criteria:

• diagnosed as xerophthalmus
• diagnosed as other eye diseases or systemic diseases