The induction of lens opacities by ionizing radiation and other agents is well known. Quantitative comparison of the results of different investigations is hampered, however, by the lack of a standard system of classification. The following is a grading system that has proved useful in our laboratory for recording the extent of injury of the mouse lens.
In earlier experiments, we recorded our observations on lens changes by sketching the appearance of the lens. This method, however, was unsatisfactory for comparative and statistical purposes. Hence, a numerical grading system was set up by which the opacities were divided into four grades of severity, ranging from one ( + ) to four ( + + + +).1-3 Subsequently, we further refined the grading system by estimating the proportion of the lens appearing to be opacified on slit-lamp examination, scoring the estimate on a scale of 0% to 100%.4 The details of this technique are summarized in the
CHRISTENBERRY KW, UPTON AC, CONKLIN JW. Recording Lens Opacities. Arch Ophthalmol. 1964;72(5):667-669. doi:10.1001/archopht.1964.00970020667016