We are developing objective and subjective methods to monitor and document opacities in the human lens using different systems. We are presently actively recruiting patients with and without cataracts for reproducibility studies on the objective systems-- the Scheimpflug cameras (Zeiss and topcon), Retroillumination camera (Neitz), Specular microscope (Keeler) and laser light- scattering spectroscope (KOWA). We will also test other systems using sound (ultrasonography), and nuclear magnetic resonance (magnetic resonance imaging). We are also studying subjective systems or methods, such as the effects of cataracts on visual perception, contrast sensitivity, and glare, which may be useful as additional parameters in the monitoring of cataract presence, progression, or regression.