Young rat lenses were incubated in organ culture media enriched with 20 mM calcium. Lenses in the calcium rich medium developed cataracts and were characterized by the absence of vimentin in the urea soluble protein fractions. Sections from the same lenses were studied by polarized light scattering. The I+/Iparallel scattering intensity ratios were higher from the lenses in calcium-rich media than from the control lenses. This indicated an increase in the optical anisotropy fluctuations during cataractogenesis. The turbidity that developed due to these fluctuations was caused partly by the disappearance of vimentin and which in turn caused the enhancement of birefringence of the lens.