Basing on the bipolar-coaxial wetfield-diathermy, introduced in microsurgery 1974 by the author, an anterior capsulotomy instrument using a modulated RF-current was published in 1984. In the meantime several patients have been operated successfully with this technique. However, further experimental studies allowed a refining of the instrument, an improvement of the electronic control device and a perfection of the surgical technique. Today, this technique has four considerable advantages compared with other methods: the size of the capsulotomy opening is not casual but determined by the surgeon, the presence of a viscous substance in the anterior chamber definitely facilitates the optical control of the surgical procedure, the border of the capsulotomy is astonishingly resistant to mechanical forces, therefore the risk of radial capsular tears is highly reduced, the border of the capsulotomy is well defined by a tiny grayish coagulation line which facilitates the implantation. The experimental results are demonstrated. The clinical and surgical results are presented in the same journal by Coester et al.