Non-penetrating glaucoma surgeries, namely deep sclerectomy and viscocanalostomy, work by enhancing the natural aqueous outflow channels by reducing outflow resistance. Outflow resistance to aqueous is constituted by trabecular meshwork, which contributes 75% of resistance and by outer wall of Schlemm’s canal, which constitutes rest of 25%. Fydorov and Koslov are credited with creating resurgence in non-penetrating deep sclerectomy during 1980s. In non-penetrating deep sclerectomy deep scleral flap, outer and inner wall of the Schlemm’s canal and juxtacanalicular meshwork are removed thereby removing the main sources of outflow resistance. The major advantage of non-penetrating deep sclerectomy is that precludes the sudden hypotony that occurs following trabeculectomy by creating progressive filtration of aqueous humor from the anterior chamber to the subconjunctival space, without perforation of the eye. As in trabeculectomy, non-penetrating deep sclerectomy also shows a waning effect with time and supplemental medications and/or repeat surgery are required in more than 50% after 4–5 years. Non-penetrating deep sclerectomy scores over trabeculectomy in safety issues as it does not cause shallow anterior chamber, inflammation, cataract and bleb-related issues. However, it only works in variants of open-angle glaucoma and should not be attempted in angle-closure glaucoma.