The lens opacity meter: a method of quantification of lens opacity by measurement of scattering of incident light.

The Lens Opacity Meter (LOM) has been developed as a method of quantifying lens opacity. It was compared both with a photographic system and with measured visual acuity. The LOM is a simple system to operate and requires minimal training. LOM readings were correlated with the presence and severity of nuclear opacity and also total cataract grade. It also showed a correlation with visual acuity. LOM readings were not useful in documenting the presence or severity of cortical or posterior subcapsular opacity, and in these cases there was considerable variation in the LOM readings. These data suggest that the LOM may be of limited value as a simple screening test, but it has limited use in discriminating between various types of severity of opacities.