Statistics of cataract operations can be made from different points of view. It is plain that complicated cases do not give as favorable results as uncomplicated ones, and therefore almost all statistics refer only to uncomplicated cataracts. Yet this does not make them comparable with one another, for Dr. A. will count cases among the complicated which Dr. B. will consider uncomplicated. To present a faithful picture of what an operator has accomplished, all his operations should be counted, or if he excludes some he should supplement his statistics by a special report, best with abstracts of the cases.
Another point in which reports differ is the standard of success and failure. Shall we make success dependent on the acuteness of sight, or on the perfection of the recovery? Sometimes we have to extract lenses from incurably blind eyes, say a chalky, partially or totally dislocated lens in a young