ABSTRACTPurpose/aim of the study: To observe and analyze the weekly changes in morphology and size of vacuoles, so called Wedl cells, in eyes with posterior subcapsular cataract (PSC).Materials and methods: Thirty-six eyes of 36 patients with pronounced PSC were included in this prospective study. High-resolution retroillumination images were taken, and the changes in size and shape of Wedl cells were analyzed at baseline and at 2 and 4 weeks later using dedicated imaging software.Results: In total, 1087 Wedl cells were observed. Within 2 and 4 weeks, 31 and 22 Wedl cells appeared and 13 and 40 Wedl cells disappeared, respectively. Median Wedl cell size at baseline and after 2 and 4 weeks was 4000 µm2 (range: 40–212120 µm2), 4080 µm2 (range: 40–274520 µm2), and 4160 µm2 (range: 40–212200 µm2), respectively. For the absolute size change within 4 weeks, a significant difference was observed (p = 0.045). The median change in absolute solidity within 2 and 4 weeks was 0.01 (range: 0.00–0.19) and 0.02 (range: 0.00–0.53), respectively.Conclusions: Wedl cells undergo morphological changes within a short time period of 4 weeks and even appearance and disappearance of Wedl cells can be observed within weeks. The fact that spontaneous regression occurs may, when properly understood, have some relevance for the development of therapeutical approaches to reverse existing PSC in the future.