目的 探讨成人的正视化机制，了解成人各屈光因子的年龄变化规律。方法 将129例正视状态健康成人按年龄分为四组：A组为20~29岁，B组为30~39岁，C组为40~49岁，D组为50岁以上，使用OrbscanⅡ角膜地形图系统测量各组屈光介质参数：角膜总屈光力、角膜前表面屈光力、角膜后表面屈光力、中央角膜厚度、前房深度、晶状体总屈光力、晶状体前表面屈光力、晶状体厚度及眼轴长度，并进行比较。分析各参数随年龄的变化特点。分析各参数的OrbscanⅡ角膜地形图系统测量值与正常值的差异。结果 随着年龄的增大，眼轴逐渐变短，但同时伴有角膜、晶状体屈光力的增大及前房深度的变浅，从而维持了正视状态，此外晶状体的增厚、曲率的变大及前房的变浅可能通过屈光指数的减小同样维持了正视状态。除角膜后表面屈光力及中央角膜厚度外，各屈光因子均表现出一定的年龄变化规律。OrbscanⅡ角膜地形图系统具有一定的测量误差。 结论 成人眼的正视化是一个复杂的多环节的过程，是各因素协调配合的结果。应充分认识OrbscanⅡ角膜地形图系统的测量误差，避免对临床工作的不良影响。

【Abstract】 Objective To discuss the mechanisms of emmetropization of adult eye and identify the aging rules of the refractive components. Methods The healthy emmetropic subjects， divided into four groups according to the age ,were detected by Orbscan Ⅱ corneal topographic system.The refractive parameters were compared among the four groups ,including total corneal and lens refractive power、anterior and posterior corneal surface power、central corneal thickness、anterior chamber depth、 anterior lens surface power、lens thickness and axial length.The characters of the change dependent on age in every parameter were analyzed .The refractive component values measured by the the Orbscan Ⅱ corneal topographic system were compared with the standard ones. Results The axial length of the eye decreased during the adult years of life gradually ,concurrently with increases in the corneal and lens refractive power and a decrease in the anterior chamber depth,that maintained emmetropia.Furthermore,the steeper and thicker lens ,shallower anterior chamber contributed to the emmetropia with the help of the decrease in refractive index of len.With the increase of age,most refractive factors changed by rule, except the