Responses were obtained from 12 subjects (24 eyes) who wore 2 types of 13.6-mm diameter Bausch & Lomb Soflens“ contact lenses-thin F3 lenses and conventional-thickness F3 lenses. These responses were also compared with those of patients who had worn thin F lenses that were 12.5 mm in diameter. Fewer patients experienced discomfort or corneal changes with the thin F3 lenses than with the conventional ones. Lens diameter was also an important factor in improving the patients' responses. Only 35% of a different sample of 23 patients who had been fitted with 12.5-mm diameter thin F lenses had been able to wear them successfully, compared with 75% of those wearing the 13.6-mm diameter thin F3 lenses, even though the mean corneal thickening caused by the smaller lenses did not differ significantly from that caused by the thin F3 lenses. Thin hydrogel lenses with diameters larger than 13.6 mm thus might produce an even better overall patient response while still causing minimal corneal edema.