Intravitreal use of vital dyes in combination with the action of endoillumination can induce a cyto- and phototoxic effect on posterior eye segment structures. The search for a staining agent with a maximum safety profile to retinal structures, intensively and selectively coloring vitreous body and vitreoretinal interface structure, remains relevant.Objective: to determine comparative viability of NIH / 3T3 mouse fibroblast cell culture with traditional agents for chromovitrectomy and “Vitreocontrast” suspension with and without endovitreal illumination.Materials and methods. NIH / 3T3 mouse fibroblast cultures contacted with agents for chromovitrectomy (MembraneBlue® Dual, Triamcinolone acetonide, “Vitreocontrast” suspension) and the corresponding controls in a volume of 50 μl / well. The test plate was irradiated with a Photon II illuminator (Synergetics, USA), working distance of 5 mm. The control tablet with the introduced preparations was not exposed to light. Next, the cells were washed and incubated, after which the morphology and lysis of the cells, as well as the number of proliferating relatively negative control of fibroblasts, were evaluated using the vital dye PrestoBlue Cell Viability Reagent. Negative control was the complete growth medium for the cultivation of mouse fibroblasts of the NIH / 3T3 line. The results of the cytotoxic reaction of a culture of mouse fibroblasts of the NIH / 3T3 line were interpreted using the table “The degree of cell response”.Results. Studies have shown that exposure to a source of endovitual illumination does not affect the cytotoxic effect of TA suspension and MembraneBlue® Dual dye. The TA suspension, both after light source and without it, has a moderate cytotoxic effect, and MembraneBlue® Dual has no cytotoxic effect on the culture of mouse fibroblasts of the NIH / 3T3 strain. Without light, “Vitreocontrast” suspension does not have cytotoxic effect on mouse fibroblasts culture NIH / 3T3 line. Light irradiation for 1 h increases the cytotoxicity of “Vitreocontrast” suspension to the level of unsharp cytotoxicity allowed by ISO Standard 10993-5-2011.Conclusion. The safety profile of MembraneBlue® Dual and “Vitreocontrast” suspension allows them to be recommended for use in endovitreal surgery. The cyto- and phototoxicity demonstrated in the experiment with TA suspension can reduce the functional outcomes of retinal surgery.