Modern functional and anatomic tests allow a reproducible approach of congenital abnormalities of the anterior segment in pediatric patients. Bidimensional ultrasonography allows to perform accurate IOL determination based on precise localization of the macula. In congenital glaucoma, it allows to evaluate optic disc cupping when retinal biomicroscopy is not possible. Color doppler ultrasonography enables to assess blood flow of intra-ocular vessels (in case of persistence of primitive vitreous) or of retrobulbar vessels (in eyes with congenital glaucoma). Miniaturization has allowed to adapt a great number of devices, such as an automatic refractometer, a tonometer, a retinograph or an angiograph, for the use in patients in prone position. These techniques have allowed to assess the anatomic and functional status of eyes undergoing surgery for congenital cataract, which is based on an anterior and posterior capsulorhexis followed by central vitrectomy, for congenital glaucoma, using modern goniotomy or external trabeculotomy, or for anterior persistence of primitive vitreous treated with membranectomy.