This study will use a newly developed instrument called dynamic light scattering device (DLS) to examine age-related changes in the human lens and to study the causes and development of cataracts. DLS uses a low intensity laser light (similar to that used in supermarket checkouts) to measures lens cloudiness. It detects changes in the human lens at the earliest stages, when anti-cataract treatment would be most effective in reversing, delaying or preventing cataract formation.