Harris W F
Department of Optometry, Rand Afrikaans University, Johannesburg, South Africa.
Am J Optom Physiol Opt. 1988 Oct;65(10):794-802. doi: 10.1097/00006324-198810000-00003.
Sphero-cylinders and refractive errors can be represented by matrices. Matrix algebra provides methods whereby sphero-cylinders can be added, subtracted, multiplied, inverted, and raised to powers and can have roots extracted. These operations are defined for sphero-cylinders and examples are given. In terms of these operations a number of means of refractive errors are defined: the arithmetic, harmonic, and quadratic means. Furthermore it is possible to define a variance and standard deviation for refractive errors. These quantities should provide a basis for a formal approach to the statistical analysis of populations of refractive errors.
球柱镜和屈光不正可用矩阵表示。矩阵代数提供了一些方法，通过这些方法可以对球柱镜进行加、减、乘、求逆、乘幂以及开方运算。这些运算针对球柱镜进行了定义，并给出了示例。根据这些运算定义了一些屈光不正的均值：算术均值、调和均值和二次均值。此外，还可以为屈光不正定义方差和标准差。这些量应为屈光不正人群的统计分析提供一种正式方法的基础。
