Weissman B A
Am J Optom Physiol Opt. 1986 Jul;63(7):536-8.
Toric hydrogel contact lenses are used when spherical lenses prove inadequate at correcting refractive error due to astigmatism. A model of hydrogel contact lens flexure effects allows theoretical investigation of the in situ optical power of toric soft contact lenses. Total meridional power is believed to be the sum of meridional lens power and entrapped tear layer power if any, and not due to lens form or flexure when considering low-minus powered lenses. The clinician should reduce astigmatic power correction both to allow for minus tear lens effects in thicker meridians and to decrease variable visual results due to misrotation.
当球形镜片在矫正因散光引起的屈光不正时被证明不足时，就会使用复曲面水凝胶隐形眼镜。水凝胶隐形眼镜弯曲效应模型允许对复曲面软性隐形眼镜的原位屈光力进行理论研究。如果考虑低度数镜片，总子午线屈光力被认为是子午线镜片屈光力和截留泪液层屈光力（如有）之和，而不是由于镜片形状或弯曲。临床医生应减少散光屈光力矫正，既为了考虑较厚子午线中的负性泪液镜片效应，也为了减少因旋转错误导致的视觉结果变化。
