Purpose: To study a prototype of an ultrasound-based vitrector, and to try to understand the physical phenomena underlying this new technology. Methods: We tested the ultrasound-based vitrector prototype (UV) (ultrasonically-driven handpiece obtained from a modified version of the Alcon CONSTELLATION Vision System [Alcon]) using an automatic experimental setup. Balanced saline solution (BSS) and vitreous (from fresh postmortem enucleated porcine eyes) flow rates were analyzed using three different tips. Results: In general, BSS solution flow rates increased with increasing aspiration levels and decreased when we used % US power. Vitreous flow rates were influenced by aspiration levels, % US power, and ultrasound-related phenomena: cavitation phenomenon and “jet streaming.” Conclusion: Ultrasound-based vitrectomy may represent an important alternative to traditional vitrectomy. Such a tool, capable of liquefying and excising the vitreous body using ultrasound, could overcome all the limits of the guillotine-based technique (GV). Knowledge of the physical phenomena underlying ultrasound-based technology is a necessary prerequisite for further development of this new technology.