The lens opacity meter, a recently developed clinical device for the examination of cataractous lenses, was used to evaluate nuclear opacification. In 215 noncataractous lenses of subjects aged 6–86 years, the opacity value (OV) ranged from 5.2 to 24.8 and increased with ageing. The OV measured in cortical cataracts with intrapupillary opacification was relatively higher than that without opacities. The scattered light intensity of the nuclear zone, measured from a Scheimpflug image, correlated well with the OV. In some cases with noncataractous eyes, the correlation between small-sized protein particles and the OV was examined. The lens opacity meter is useful to objectively evaluate changes in nuclear opacity.