Retinal vein occlusion (RVO) is a major cause of vision loss in patients over 50 years old. RVO can be treated by cannulation of the retinal vein to remove clots. However, cannulation of small retinal veins is challenging as the required puncture force (~10 mN) is well below human sensing capability [1]. In this paper, we introduce a passive compliant tool for retinal vein cannulation having predetermined stroke and threshold force which allows safe and precise puncturing independent of actuation input. Our tool can be utilized in either stand-alone mode or mounted onto a robotic system.