DESPITE the fact that in the severest cases of hyperglycemia the crystalline lens is clear enough to allow adequate visualization of the deeper structures, there is a deep-rooted belief that a relationship exists between cataract and diabetes. Ancients knew that an excessive amount of sugar in the urine is a pathologic condition. They also were aware that opacity of the lens, presently known as cataract, unless it is removed, may cause blindness. Hindu physicians far back in antiquity recognized diabetes mellitus by observing that flies and insects fed on the urine of certain patients. Susruta, the father of Indian surgery, was familiar with both the clinical picture of the disease and with the sweet taste of the urine of diabetic persons. Diabetes was, and still is, a disease prevailing among the Hindus.
Cataract was recognized as a serious ocular lesion by the Egyptians still earlier (probably by 3500 B. C.).
GORDON BL. EFFECTS OF DIABETES ON CATARACT AND ON VISION. Arch Ophthalmol. 1949;41(4):462-472. doi:10.1001/archopht.1949.00900040472009