"Jelly-bump" deposits, which are composed mainly of lipids, on high water content, extended-wear hydrogel lenses, are a clinically significant problem of unknown etiology. The authors explored the effect of nutrition on the frequency of deposition of these jelly bumps. Forty-three patients were included in this masked case-control study from five contact lens practices in North America. Thirty patients were lipid-depositor cases and 13 were controls. Tear specimens were drawn and analyzed for potassium by atomic-absorption spectrophotometry. Detailed dietary histories were conducted and diet nutrient composition was computed. Patients with diminished tear-potassium concentrations have an increased risk of jelly-bump deposition. Elevated intake of protein, alcohol, and cholesterol also appeared to be correlated significantly with increased jelly-bump deposition. The authors found that diabetics and the use of diuretics, anticholinergics, sympathomimetics, were associated with tear-film potassium depletion and lipid deposit formation.