Figure 1. The exposure of visible light causes injury in retinal ganglion cell (RGC)-5 cells. A: The effect of visible light on the viability of RGC-5 cells over periods of 1–3 days was determined with the MTT assay. Results are expressed as a percentage of the control and are the means±SEM (n=48, three individual cultures). B: The percentage of dead cells was monitored from 1 to 3 days with PI staining. The results are the means±SEM (n=18, three individual cultures) (***p<0.001, one-way ANOVA and Bonferroni test). C-F: PI staining was used to show cell death. RGC-5 cells were exposed to 2,600 lx visible light for 1 day (C), 2 days (D), 3 days (E), or no light as a control (F). Dead cells were stained in red and are denoted with arrows (>). Scale bars=50 μm.