Kim Eon, Bakaraju Ravi C, Ehrmann Klaus
*PhD †PhD, FAAO Brien Holden Vision Institute, Sydney (EK, RCB, KE); and School of Optometry and Vision Science, University of New South Wales, Sydney, Australia (RCB, KE).
Optom Vis Sci. 2017 Feb;94(2):183-196. doi: 10.1097/OPX.0000000000000998.
To evaluate the optical power profiles of commercially available soft multifocal contact lenses and compare their optical designs.
The power profiles of 38 types of multifocal contact lenses-three lenses each-were measured in powers +6D, +3D, +1D, -1D, -3D, and -6D using NIMO TR1504 (Lambda-X, Belgium). All lenses were measured in phosphate buffered saline across 8 mm optic zone diameter. Refractive index of each lens material was measured using CLR 12-70 (Index Instruments, UK), which was used for converting measured power in the medium to in-air radial power profiles.
Three basic types of power profiles were identified: center-near, center-distance, and concentric-zone ring-type designs. For most of the lens types, the relative plus with respect to prescription power was lower than the corresponding spectacle add. For some lens types, the measured power profiles were shifted by up to 1D across the power range relative to their labeled power. Most of the lenses were designed with noticeable amounts of spherical aberration. The sign and magnitude of spherical aberration can either be power dependent or consistent across the power range.
Power profiles can vary widely between the different lens types; however, certain similarities were also observed between some of the center-near designs. For the more recently released lens types, there seems to be a trend emerging to reduce the relative plus with respect to prescription power, include negative spherical aberration, and keep the power profiles consistent across the power range.
评估市售软性多焦点隐形眼镜的屈光力分布，并比较它们的光学设计。
使用NIMO TR1504（比利时Lambda-X公司）测量38种多焦点隐形眼镜（每种镜片3片）在+6D、+3D、+1D、-1D、-3D和-6D屈光力下的屈光力分布。所有镜片均在直径8mm的光学区内在磷酸盐缓冲盐水中进行测量。使用CLR 12-70（英国Index Instruments公司）测量每种镜片材料的折射率，该仪器用于将在介质中测量的屈光力转换为空气中的径向屈光力分布。
确定了三种基本类型的屈光力分布：中心近用、中心远用和同心环型设计。对于大多数镜片类型，相对于处方屈光力的相对正度数低于相应的框架眼镜附加度数。对于某些镜片类型，在整个屈光力范围内，测量的屈光力分布相对于其标记的屈光力最多偏移1D。大多数镜片设计有明显的球差量。球差的符号和大小可以与屈光力相关，也可以在整个屈光力范围内保持一致。
不同镜片类型之间的屈光力分布差异很大；然而，在一些中心近用设计之间也观察到了某些相似之处。对于最近推出的镜片类型，似乎出现了一种趋势，即降低相对于处方屈光力的相对正度数，引入负球差，并使屈光力分布在整个屈光力范围内保持一致。
