Measured and laboratory-stated parameters of hydrophilic contact lenses

One hundred thirty-one new hydrophilic lenses made by 3 manufacturers were randomly selected from an optometry clinic for measurement and inspection. Approximately 60% of the base-curve specifications fell within the following ranges for the measured dimensions: Bausch & Lomb Soflens contact lenses, less than 0.150 mm; Milton Roy Naturvue lenses, less than 0.375 mm; Soft Lens Inc. Hydrocurve, less than 0.225 mm. More than 65% of the lenses supplied by all the manufactures were within 0.25 D of the power specification. About two-thirds or more of all lenses had a central thickness and overall diameter within 0.04 mm and 0.40 mm, respectively, of the manufacturers' specifications, although there were notable differences among manufacturers. Most of these new lenses exhibited surface scratches and other surface defects, and many lenses had edge defects.