Clinical Applications of Power Vectors
- 1 June 2009
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Optometry and Vision Science
- Vol. 86 (6), 599-602
- https://doi.org/10.1097/opx.0b013e3181a6a211
Abstract
The study of infant vision is closely coupled to the study of the refraction, change in refraction over time, and the effect of spectacle correction on visual development. Frequently, reports are limited to descriptions of spherical equivalent or cylinder power without regard to axis, as data are frequently collected in the clinical format of sphere, cylinder, and axis (S, C, A). Conversion from clinical notation to a power vector representation of refraction allows unambiguous description of how refractions change over time and differ between repeated measurements. This article presents a series of examples of Microsoft Excel spreadsheet formulas that make the conversion from clinical notation to power vector format, and provides examples of useful applications of these methods.Keywords
This publication has 10 references indexed in Scilit:
- Measurement of Refractive Error in Native American Preschoolers: Validity and Reproducibility of AutorefractionOptometry and Vision Science, 2000
- Astigmatism and Amblyopia among Native American Children (AANAC): design and methodsOphthalmic Epidemiology, 2000
- Reproducibility and accuracy of measurements with a hand held autorefractor in childrenBritish Journal of Ophthalmology, 1997
- Power Vectors: An Application of Fourier Analysis to the Description and Statistical Analysis of Refractive ErrorOptometry and Vision Science, 1997
- Clinical Refraction in Three-Dimensional Dioptric Space RevisitedOptometry and Vision Science, 1997
- Reproducibility of corneal astigmatism measurements with a hand held keratometer in preschool children.British Journal of Ophthalmology, 1995
- Algebra of Sphero-Cylinders and Refractive Errors, and Their Means, Variance, and Standard DeviationOptometry and Vision Science, 1988
- Lens Effectivity in Terms of Dioptric Power MatricesOptometry and Vision Science, 1981
- A Remote Subjective Refractor Employing Continuously Variable Sphere-Cylinder CorrectionsOptical Engineering, 1976
- A Matrix Formalism for Decentration ProblemsOptometry and Vision Science, 1976