Variables associated with ultraviolet transmittance measurements of intraocular lenses

We measured the spectral transmittance of 12 intraocular lenses with a spectroradiometer system that uses an integrating sphere input. We evaluated both low- and high-power lenses and varied the input aperture size between 1, 3, and 5 mm. These variations caused a significant difference in the transmittance characteristics of the intraocular lenses. Most significantly, the transmittance of the low-power model was two to six times greater than that of the high-power model in the cutoff region. The larger aperture resulted in, at most, a factor of two difference in transmittance. This effect was observed in intraocular lenses labeled both ultraviolet-absorbing and nonultraviolet-absorbing.