A new method of analyzing vectors for changes in astigmatism
Related Experiment Video
Updated: Nov 7, 2026

Subjective Refraction Test Using a Smartphone for Vision Screening
Published on: October 18, 2024
1Cheltenham Eye Centre, Melbourne, Victoria, Australia.
Abstract:
This method of astigmatism analysis recognizes the need to define an astigmatism goal, thus allowing the surgeon to obtain precise, separate measures of the magnitude and the angle of surgical error. From this, the surgeon can evaluate what surgery may be required to achieve the initial preoperative goal. An index that measures surgical success is adjusted for the level of preoperative astigmatism. The resulting data allow statistical comparison of multiple surgeries and techniques. This method also assists in resolving the case when spectacle and corneal astigmatism do not coincide.
Related Concept Videos
Lines in Space
Vector Algebra: Method of Components
In many applications, the magnitudes and directions of...
Vector Algebra: Graphical Method
We use the laws of geometry to construct resultant vectors, followed by trigonometry to find vector magnitudes and directions. For a geometric construction of the sum of two vectors in a plane, we follow the parallelogram rule. Suppose two vectors are at arbitrary positions. Translate either one of...
Vectors
Vectors in 2D: Problem Solving
Direction Cosines of a Vector