Dark refraction shift with allowance for astigmatism

African Vision and Eye Health

Field Value
Title Dark refraction shift with allowance for astigmatism
Creator Gillan, W.D.H.
Subject — dark refraction shift, dark focus, multivariate methods, stigmatic, antistigmatic, polar profiles
Description Purpose: To show that the dark refraction shift (dark focus) is a more complicated phenomenon than implied when presented as spherical. Methods: Fifty autorefractor measurements of refractive state of the right eye were obtained in light  and  dark  conditions.  Multivariate  methods were used to analyze the data and stereo-pair scat-ter plots, polar meridional profiles and other means of presenting results are used to show important characteristics of the dark refraction shift. Results: The complexity of the dark refrac-tion shift is indicated by stereo-pair scatter plots showing the amount of stigmatic and antistigmatic variation that occurs in light and dark conditions. The mean dark refraction shift is presented in a complete manner including all three components of refractive state. The greater variance and covari-ance under dark conditions is clearly shown by the term-by-term dark-light variance-covariance ratio and polar profiles  of variance and covariance.Conclusions: The  dark  refraction  shift  is  a more complicated phenomenon than implied by representations as purely spherical in nature.
Publisher AOSIS
Date 2005-12-19
Type info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion — —
Format application/pdf
Identifier 10.4102/aveh.v64i1.206
Source African Vision and Eye Health; South African Optometrist: Vol 64, No 1 (2005); 26-30 2410-1516 2413-3183
Language eng
The following web links (URLs) may trigger a file download or direct you to an alternative webpage to gain access to a publication file format of the published article:

Coverage — — —
Rights Copyright (c) 2005 W.D.H. Gillan https://creativecommons.org/licenses/by/4.0