随着白内障手术由复明性向屈光性转变，对角膜的散光矫正显得越来越重要。而角膜散光不仅仅应该关注角膜前表面的散光数据，更应该考虑角膜后表面的散光，否则对散光人工晶状体植入矫正角膜散光可能出现不同程度的术后屈光误差。角膜后表面散光均值约为0.37 D，且多数情况下会产生逆规散光的效果，因此在进行散光型人工晶状体计算时应考虑到这一特点，进一步防止术后欠矫或过矫的发生。

With the cataract surgery evolving from visual restoration surgery to refractive surgery, surgical correction of corneal astigmatism becomes more and more important. For Toric intraocular lens implantation, the surgeon should not only pay attention to the values in surface of anterior corneal astigmatism but also that in posterior corneal astigmatism. Otherwise,unwanted postoperative refractive errors may occur. The mean value of posterior corneal astigmatism was around 0.37 D.In most cases, the posterior corneal astigmatism produces against-the-rule effect. Therefore, the above-mentioned feature of posterior corneal astigmatism should be noticed to prevent the under-correction or over-correction effect of toric lens.