Bilingual edition: English is preserved and Chinese follows each unit. Terminology uses the confirmed v20260916 glossary; automated semantic review remains traceable.
中英双语版：英文原文完整保留，中文紧随对应单元；术语采用 v20260916 确认表，自动语义审校结果可追溯。

Front and Back Vertex Power

前顶和后顶功率

Once the equivalent power and the front and back vertex powers are obtained, the associated focal lengths can be found by just taking the reciprocals of the powers. Note that Gullstrand's equation can be used for either two lenses (with n=1) or two surfaces.

一旦获得等效功率以及前表面和后表面的功率，就可以通过取功率的倒数来找到相应的焦距。注意，Gullstrand方程可以用于两个棱镜（n=1）或两个表面。
Calculations
计算
 Index

Lens concepts
棱镜概念索引
 
HyperPhysics***** Light and Vision
HyperPhysics ***** 光与视觉
R Nave
 Go Back
返回