Proton pulsed gradient spin echo (PGSE) nuclear magnetic resonance (NMR) spectroscopy was used to explore the free and restricted non-Brownian nature of lens water self-diffusion in calf lens tissue. At all temperatures investigated the water self-diffusion coefficient (Dw) of the cortical homogenate (25% protein) was 1.6-1.7 times greater than that for the nucleus (42% protein), and 0.3-0.5 times the value of Dw for pure water. The nuclear lens homogenate displayed anomalous temperature dependent water diffusion behavior, i.e. a departure from the smooth monotonic decrease in Dw with decreasing temperature, in the temperature range of 3-5 degrees C. By contrast, no such behavior was observed for cortical homogenate. Analysis of water proton echo attenuation data employing a parallel-plate model of restricted diffusion provided values for the parallel-plate barrier separation and self-diffusion coefficient in the limit of free diffusion. Nuclear material showed a smaller spatially average barrier separation and a significantly stronger barrier separation temperature dependence than cortical material.