Effect of low voltage on electrical properties of eye lens.

In the present study, the Cole-cole plot of lens tissue has been drawn using AC impedance system (EG and G PARC Model 318) in the frequency range 10 mHz to 10 Hz at low voltage stress. The impedus locus between real part (Z') and imaginary part (Z") of complex impedance of lens was examined. Results showed that the extracellular resistance (Re), distribution factor (alpha) and depressed angle (theta) were significantly varied at experimental low voltages. An attempt has been made to explain the electrical data of voltage-tissue interaction on the basis of solid state biophysics.

Near ultraviolet radiation induced changes in goat lens.

The possibility that the ultraviolet radiation from sunlight and other ambient sources as a major causative factor for the onset of cataract processes and photolytic changes of the eye lens constituents was studied. Normal goat lenses exposed in vitro to near UV radiation in the region of 315-400 nm (UV-A) revealed distinct morphological changes in the ultrastructure, increase in the inorganic elements; C, H, N, and a sharp shift in the intrinsic fluorescence spectra. UV exposure resulted in an alteration in the lambda max of the excitation spectra, a red shift in the emission absorption maxima and also an increase in the absolute fluorescence intensity. Scanning electron microscopic study showed a significant increase in the interfibrillar distances of the lens structural proteins. It is argued that the UV light induced covalent modifications of the lens proteins and their aggregations might have occurred due to the generation of photolytic products which then lead to oxidative damages.