Document Detail


Relationship between visual acuity and observation distance.
MedLine Citation:
PMID:  7724215     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The visual acuities of 17 young emmetropes and corrected ametropes were measured over the range of 7.5-0.19 m using a Bailey-Lovie chart. Accommodation stimulus-response measures were also taken over this range using retinoscopy to establish whether variations in visual acuity with observation distance could be attributed to accommodation behaviour. Tonic accommodation was recorded using the Canon R1 autorefractor and was compared with visual acuity and stimulus-response results. In general, visual acuity was found to be dependent on stimulus distance, being significantly reduced for most observers for the closest targets. There were three categories of observer performance for visual acuity as a function of observation distance; one group showing no change in visual acuity with distance, a second showing a flat function for distances 7.55-0.5 m, and then a decrease in visual acuity for shorter distances; and a third category that showed a maximum visual acuity in the 1.2-1.6 m region. This behaviour was unrelated to individual stimulus-response characteristics and there was no significant relationship between tonic accommodation and the distance where acuity was best for the third category observers.
Authors:
G Heron; H P Furby; R J Walker; C S Lane; O J Judge
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)     Volume:  15     ISSN:  0275-5408     ISO Abbreviation:  Ophthalmic Physiol Opt     Publication Date:  1995 Jan 
Date Detail:
Created Date:  1995-05-25     Completed Date:  1995-05-25     Revised Date:  2006-11-07    
Medline Journal Info:
Nlm Unique ID:  8208839     Medline TA:  Ophthalmic Physiol Opt     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  23-30     Citation Subset:  IM    
Affiliation:
Department of Vision Sciences, Glasgow Caledonian University, UK.
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MeSH Terms
Descriptor/Qualifier:
Accommodation, Ocular / physiology
Adolescent
Adult
Distance Perception / physiology*
Humans
Refractive Errors / physiopathology
Vision Tests / methods
Visual Acuity / physiology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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