Tinted hydrogel lenses permanency of tint

The spectral transmittances of a sample group of tinted hydrogel contact lenses were analyzed to assess the reproducibility of tinted lenses of a given density. Transmittance data were used to assess permanency of the tint after a 14-day cycle of daily cleaning, sterilization, and storage using a variety of cleaning and sterilization treatments. One-way analysis of variance of the transmittance data has demonstrated significant variations in the density of tint for Cibasoft lenses of a given color and density. However, these variations are smaller than the manufacturer's stated criterion for acceptable differences in tint density at a given tint level, i.e., light, medium, or dark. The Cibatint is stable when the lenses are cleaned with the Septicon and Miraflow systems. However, tinted hydrogel lenses from other manufacturers demonstrated changes of tint which were dependent upon the cleaning and sterilization methods used.