Lisa (Carl Zeiss Meditec AG, Jena, Germany),2 should not be far off, and these IOLs more accurately correct preoperative astigmatism than limbal relaxing incisions.
While the ciliary body is relaxed, the two optics are relatively close together for distance vision.
As the ciliary body contracts and the zonule relaxes, the optics move apart, thus increasing the power of the lens and resulting in near acuity.
The recently introduced Tecnis Multifocal IOL (Abbott Medical Optics Inc., Santa Ana, CA) has a diffractive optic, like that of the Acry Sof Restor IOL (Alcon Laboratories, Inc., Fort Worth, TX).
The diffractive ridges of the former, however, extend all the way to the edge of the optic, which should give patients better reading ability in low-light settings such as a dimly lit restaurant.1 A major difficulty with diffractive optics is chromatic aberration, which is generally worse than with refractive optics.
Distance and near vision was equivalent with the two lenses, but the Synchrony provided significantly better binocular intermediate vision at 60 cm.