Purpose: To study whether the glistening on implanted acrylic intraocular lenses increases or not.Method: 1. Prospective study: We studied the glistening on 49 implanted acrylic intraocular lenses, particularly the time of appearance and increase after glistening appeared. 2. Experiment: We kept an intraocular lens immersed in saline solution at 50 degrees centigrade for 2 hours and then moved this lens into saline solution at 35 degrees centigrade, and observed this lens during immersion.Results: 1. Prospective study: Glistening was present in 28 eyes (57%), and appeared from 2 to 16 months postoperatively. A few months after appearance it become stable and did not increase further. 2. Experiment: On the 10th day after observation, we could see glistening on the lenses. The points of glistening were 10 µm or less in size, and did not change during 60 days of observation.Conclusion: The glistening in acrylic intraocular lenses seemed to become stable a few months after appearance. This our experimental method is useful, because it gives us glistening similar to clinical cases in a short time.