五、 波前像差的矫正在现代眼科中的应用
虽然在十三世纪人们就开始用眼镜矫正离焦，十九世纪矫正散光[26,27]，但直到目前，普通的眼镜尚不能矫正球差、彗差和一系列不规则像差。这些像差因人而异，相互作用，直接影响到视网膜成像质量。有一些矫正像差的尝试，例如用干涉条纹成象于视网膜上，可避开眼睛屈光系统像差而看到一正弦条纹。但该方法只能用于被观测物体为条栅状且在实验室完成，对改善正常视力及眼底图像无实际意义[28]。此后，角膜接触镜的诞生因可中和角膜表面的屈光异常达到部分矫正像差的目的。方法虽简单、经济，但其有效性要依赖于角膜像差在整体眼睛光学系统像差的比例大小。
最新研究显示自适应光学是最有可能矫正人眼像差的方法[14,29]。该理论是由Babcock[30]最早提出并应用于天文学， Dreher[31]使用矫形镜用于人眼。Liang等将Hartmann-Shack像差仪和矫形镜有机的结合起来，成功地使人眼像差矫正成为现实，不仅可矫正高阶像差还被用于研究视觉质量和改善视觉功能。
自适应光学的基本原理是先准确测量出人眼像差，由计算机将像差转换为不同信号并控制一系列矫形镜使在瞳孔区的光线曲折，矫正像差。最近有实验认为自适应光学不仅可矫正单色像差亦可矫正色像差。借助自适应光学原理可获得高分辨率的视网膜图像，目前已研究用于眼底照相、视网膜及中央神经系统功能的检查。通过此方法已成功地获得活体人眼视锥细胞清晰的图像，并可根据对波长的敏感程度将锥体细胞分短波敏感、中波敏感和长波敏感三类细胞[32]，这无疑会对视网膜疾病的诊断和治疗产生重要意义。
最近一个时期，由波前像差技术引导的屈光手术是令人激动的技术之一。Seiler等人[33]最先治疗3只眼，手术后高阶像差不仅没有增加，而且可使原有高阶像差减少27%，裸眼视力2只眼2.0，另1只眼达1.6。后来，Mrocher等[34]在对28人35眼观察3个月，93.5%裸眼视力在1.0以上，超常视力(最佳矫正视力在2.0或更好)的获取率16.0%。高阶像差得到不同程度的矫正，彗差矫正结果优于球差。虽然结果令人鼓舞，但正像所有新技术一样，波前技术引导的屈光手术还需要不断的改进和完善。同时，需要对其安全性和和稳定性做更长时间的随访。此外，波前像差的有关技术还活跃于其它方面，有人设想波前像差仪可能替代传统的验光仪器。目前，研究涉及角膜晶状体像差产生的根源、视敏度、视觉分辩力、近视眼形成与像差的关系等。
总之，人们对光学像差的兴趣是建立在现代科学技术发展使传统理论得以扩展的基础上和人们对超视力的渴望。波前像差理论近年来不断发展，其应用已成为当今眼科学最活跃的领域之一[35-37]，但仍有许多问题尚需解决。例如，像差仪精确性和可重复性，调节对像差的影响，视锥细胞与像差的方向性选择问题等等[38-40]。波前引导的屈光手术尚有一些关键技术问题亟待解决。但可以肯定，波前像差理论和技术的应用，不仅对人眼视觉有了更深入的了解，而且为提高人眼视觉功能提供了新的途径和手段，具有十分重要的临床应用价值和前景。
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