Effect of optical defocus on colour perception

African Vision and Eye Health

Field Value
Title Effect of optical defocus on colour perception
Creator Sehlapelo, R. R. Oduntan, A. O.
Subject — Colour vision; Farnswoth Panel D-15 test; Visual acuity; Optical defocus; Optical blur; Refractive error
Description Daily experience shows that colour  of a very distant object cannot be accurately determined.  It is assumed that visual acuity (VA) loss is one of the factors at play in this case.  The effects of reduced VA as a result of refractive error or optical defocus on colour vision have not been examined.  Such study willdictate the need or otherwise for optical correction before assessment of colour vision.  The purpose of this study therefore, was to investigate the effects of optical defocus on colour vision in individuals with normal colour vision.  Twenty nine young adult subjects (11 male and 18 females) were included in this study. Their ages ranged from 11 to 29 years with a mean of 22.1 ± 3.4 years.  All subjects had VA of 6/6 or better and normal colour vision.  The colour vision was evaluated with the Farnsworth panel D-15 (desaturated). Each subject was optically defocused to VA of 6/24, 6/60 and 1/60(6/360) at 6 meters respectively and colour vision was assessed at each reduced VA.  At VA of 6/24, colour vision was not affected in all subjects. When the VA was reduced to 6/60, however, 15 (51%) of the subjects failed the colour vision test. When the VA was further reduced to 1/60 by optical defocus, 24 (83%) of the subjects failed the colour vision test.  It was concluded that optical defocus and reduced VA can adversely affect colour vision test findings. While VA reduction to 6/24 may not affect the colour vision results, VA of 6/60 can.  It is therefore, recommended that in clinical colour vision  testing and colour vision screening, VA should first be assessed andcompensated, especially if uncorrected VA is 6/24 or worse.  
Publisher AOSIS
Date 2007-12-19
Type info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion — —
Format application/pdf
Identifier 10.4102/aveh.v66i2.229
Source African Vision and Eye Health; South African Optometrist: Vol 66, No 2 (2007); 77-81 2410-1516 2413-3183
Language eng
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Rights Copyright (c) 2007 R. R. Sehlapelo, A. O. Oduntan https://creativecommons.org/licenses/by/4.0