Light scattering in the eye lens near the spinodal

Scattered light intensities measurements of the nuclear part of adult bovin e lenses are reported. In the investigated samples the existence of a binar y liquid phase separation from a metastable state is demonstrated by the ph enomenon of hysteresis. Fluctuations near spinodal are studied by means of a tentative theoretical approach. Accordingly the scattered light intensiti es were analyzed reduced by the intensity obtained for the stable state of the system. Fluctuations in the stable state are ascribed to protein aggreg ates and are analyzed by means of random density fluctuation theory. To eva luate the correlation length of the fluctuations near spinodal the Ornstein -Zernike theory is adopted. Temperature dependence of the correlation lengt h xi of the fluctuations near spinodal can be described by equation for cri tical fluctualions xi = xi(0) (T-T-s/Ts)(-nu). For the investigated lenses the exponent nu varies from 0.65 to 0.74 and the parameter xi(0) varies fro m 1.6 nm to 3.6 nm. The spinodal temperature T-s for the investigated sampl es is evaluated.