Neutron scattering by calf lens cytoplasm. A comparison between two models of cataract.

Small angle neutron scattering (SANS) was used to compare two models of cataracts: the cold cataract induced in the lens nucleus cytoplasm by lowering the temperature and the opacification induced by calcium in the lens cortex cytoplasm. In both cases opacified cytoplasms display additional scattering at low angles as compared to their clear controls. An analysis of this additional scattering provides quantitative information concerning the size distribution, the number and contrast of the scatterers responsible for lens opacification. The scatterers of cold cataract and of calcium--induced opacification not only have, as shown elsewhere, a different composition but are also found to display completely different sizes (in the thousand A range for cold-cataract, in the hundred A range for calcium--induced opacification). These results illustrate the diversity of scatterer types which are able to cause comparable lens opacities.