LOCS III Standard Transparency
The LOCS III transparency contains an expanded set of standard images on all four scales, and the grading scales are decimalized with each standard illustrating severity representing 1.0, 2.0, 3.0 etc. Intermediate grades (e.g.2.6) are possible with LOCS III. LOCS III has proved to be an effective means of grading longitudinal changes in each of the four features (NO, NC, C and P) of the lens, and it has been used in a wide variety of basic science applications, pharmaceutical trials, cross-sectional and longitudinal epidemiological studies, surgical studies, and in the testing and development of surgical instruments and methods (see bibliography).

The LOCS III Standard presents six slit images for grading nuclear color (NC) and nuclear opalescence (NO), five retroillumination images for grading cortical cataract (C), and five retroillumination images for grading posterior subcapsular (P) cataract. Cataract severity is graded on a decimal scale. The grading intervals are approximately equal within each scale. The simplicity of the system and its ease of use underlies its wide appeal as a simple, sensitive, validated method for assessing cataract type and severity. It has also been used widely to monitor cataract progression in longitudinal, epidemiological or pharmaceutical trials.

Each LOCS III Standard Transparency Set includes:

• Printed LOCS III grading instructions, including a comprehensive bibliography
  
  
• 8” x 10” LOCS III color transparency
  
  
• A reprint of the original article describing the development of LOCS III.