Methods and devices for minimally-invasive delivery of radiation to the posterior portion of the eye including a cannula comprising a distal portion connected to a proximal portion and a means for advancing a radionuclide brachytherapy source (RBS) toward the tip of the distal portion; a method of introducing radiation to the human eye comprising inserting a cannula between the Tenon's capsule and the sclera of the human eye and emitting the raaiation from the cannula on an outer surface of said sclera.揭示用於最小侵入性眼外遞送輻射至眼睛後部之方法及裝置,包括包含聯結至一近端部之一遠端部的一套管及用於將一放射性核種短程治療源(RBS)朝向該遠端部之梢端前進之一裝置;一種將輻射導入人眼睛之方法,包含將一套管插入於該人眼睛之眼球鞘與鞏膜間以及由該套管發射輻射至該鞏膜之一外表面上。