Cataract is associated with a diverse group of diseases, each of which has seemed to bear some causal, though undefined, relation to the changes in the lens of the eye. Diabetes, chronic nephritis with hypertension and arteriosclerosis, thyroid disease, acute infections and dental caries are among the so-called causes of cataract.1
All the foregoing diseases have a common feature in that each shows a tendency to the development of a percentage of blood sugar above the normal.
In the study of diabetes it was early established that cataract was likely to occur as a complication. But while the number of diabetic patients developing cataract is high (9 per cent., according to Williamson 2), the number of patients with cataract who have diabetes is found to be as low as 1 per cent. by de Schweinitz.3
The condition with which cataract is most often associated is found in chronic