To the Editor.
—I was fascinated by the reports of two prospective studies on cataract and cigarette smoking, and the accompanying Editorial in JAMA. However, I find two problems that I hope can be resolved. In the US Physicians Health Study, the analysis for smoking is based on 557 incident cataracts among 371 participants out of the 17824 physicians who did not report cataract at baseline, and who provided complete risk factor information.1 The same data had been analyzed previously for aspirin consumption, but then only 353 incident cataracts were claimed in the 21 316 physicians who did not report cataract at baseline.2 The later analysis has excluded more physicians but identified 204 more cataracts, although the definition of cataract appears to be the same: confirmed, age-related cataract lowering visual acuity to 20/30 or worse without another ocular disease to account for the visual loss. How can that