Abstract: To evaluate the light injury to retina, DNA changes in rabbit retina were quantitativaly studied after exposure to indirect ophthalmoscopic light. The results showed that DNA levels in the retina decreased with exposure time of light. Two days and two weeks after the light exposure, the DNA contents in the retina were significantly lower in 30 and 60 minutes exposure group, compared with the normal controls. However, the 15 minutes exposure group did not reach signifcant level of DNA reduction. The study suggests that indirect ophthalmoscopic light may damage to retina if the exposure time is longer enough.