We introduce a new device and a new technique that facilitate the clearance of postvitrectomy vitreous hemorrhage. We have developed a volume homeostatic fluid-fluid exchanger--Chen's Infusion/Aspiration (Chen's I/A) device. Due to reciprocal synchronized hydraulic action, Chen's I/A provides simultaneous infusion and aspiration of fluid of equal amounts. Therefore, it can be used to perform vitreous cavity lavage through smaller caliber needles and at the same time maintain a constant intraocular pressure. This improved vitreous cavity lavage technique is named Balanced Fluid Exchange. Performing Balanced Fluid Exchange with Chen's I/A can reduce trauma to the eyeball and decrease complications resulting from unstable intraocular pressure. Thus, it increases both the intra-operative and post-operative clearance rates of postvitrectomy vitreous hemorrhage, and is a promising method for the management of postvitrectomy vitreous hemorrhage.