Objective: To compare the possible toxic effects of three light sources used in vitreoretinal endoillumination systems; halogen, xenon, and light-emitting diode (LED) on retinal pigment epithelium (RPE) cell cultures, after two different exposure times. Material and methods: ARPE-19 human RPE cell cultures were exposed to halogen, xenon, and LED light sources at a distance of 1.5 cm for 30 and 60 min with equal lumen output levels. Cells in the control group were not exposed. RPE cell cultures were compared in terms of cell viability, DNA damage, apoptosis rate, and IL-1 ss, IL-6, and TNF- alpha levels. Results: The halogen light group showed significantly more DNA damage, higher TNF-alpha, IL-1 beta, and IL-6 levels, and lower viable cell count at 30 min compared to the control group. The rates of early and late apoptosis were also significantly higher at 60 min. There were no statistically significant differences in any of the parameters between the xenon and LED light sources and the control group at 30 or 60 min. Conclusion: New generation lights, xenon, and LED, seem to be safe in terms of RPE cells. Halogen light may cause toxic effects on RPE cells when used for a long time with maximal power output.