Compensation to positive as well as negative lenses can occur in chicks reared in bright UV lighting

Hammond, David S. and Wildsoet, Christine F. 2012, Compensation to positive as well as negative lenses can occur in chicks reared in bright UV lighting, Vision research, vol. 67, pp. 44-50, doi: 10.1016/j.visres.2012.06.021.

Attached Files
Name Description MIMEType Size Downloads

Title Compensation to positive as well as negative lenses can occur in chicks reared in bright UV lighting
Author(s) Hammond, David S.ORCID iD for Hammond, David S.
Wildsoet, Christine F.
Journal name Vision research
Volume number 67
Start page 44
End page 50
Total pages 7
Publisher Elsevier
Place of publication Amsterdam, The Netherlands
Publication date 2012-08-15
ISSN 0042-6989
Keyword(s) myopia
light intensity
UV illumination
Summary An earlier report describing a lack of compensation to imposed myopic and hyperopic defocus in chicks reared in UV lighting has led to the belief that the spatial resolving power of the UV cone photoreceptor network in chicks is not capable of decoding optical defocus. However this study used dim light rearing conditions, of less than 10 lx. The purpose of the current study was to determine if emmetropization is possible in young chicks reared under higher luminance, UV lighting conditions. Young, 4 day-old chicks were reared under diurnal near UV (390 nm) illumination set to either 20 or 200 lx while wearing a monocular defocusing lens (+20, +10, -10 or -20 D), for 7 days. Similarly treated control groups were rearedunder diurnal white lighting (WL) of matching illuminance. The WL and UV LED sources were set to equivalent illuminances, measured in ‘‘chick lux’’, calculated from radiometer readings taken through appropriate narrow band interference filters, and a mathematical model of the spectral sensitivity of the chick visual system. High resolution A-scan ultrasonography was undertaken on days 0 (before lenses were fitted), 2, 4, and 7 to track ocular dimensions and refractive errors were measured by retinoscopy on days 0 and 7. Compensation to negative lenses was unaffected by UV illuminance levels, with near full compensation being achieved under both conditions, as well as under both WL conditions. In contrast, compensation to the positive lenses was markedly impaired in 20 lx UV lighting, with increased instead of decreased axial elongation along with a myopic refractive shift being recorded with the +10 D lens.Compensation under both WL conditions was again near normal for the +10 D lens. However, with the +20 D lens, myopic shifts in refractive error were observed under both dim UV and WL conditions. The spatial resolving power of the UV cone photoreceptor network in the chick is sufficient to detect optical defocus and guide the emmetropization response, provided illumination is sufficiently high. However, compensation to imposed myopic defocus may be compromised, when either the amount of defocus is very high or illumination low, especially when the wavelength is restricted to the UV range.
Language eng
DOI 10.1016/j.visres.2012.06.021
Field of Research 111399 Ophthalmology and Optometry not elsewhere classified
11 Medical And Health Sciences
17 Psychology And Cognitive Sciences
Socio Economic Objective 970111 Expanding Knowledge in the Medical and Health Sciences
HERDC Research category C1.1 Refereed article in a scholarly journal
ERA Research output type C Journal article
Copyright notice ©2012, Elsevier
Persistent URL

Document type: Journal Article
Collections: Faculty of Health
School of Medicine
Connect to link resolver
Unless expressly stated otherwise, the copyright for items in DRO is owned by the author, with all rights reserved.

Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 11 times in TR Web of Science
Scopus Citation Count Cited 13 times in Scopus
Google Scholar Search Google Scholar
Access Statistics: 62 Abstract Views, 1 File Downloads  -  Detailed Statistics
Created: Thu, 13 Oct 2016, 09:23:53 EST

Every reasonable effort has been made to ensure that permission has been obtained for items included in DRO. If you believe that your rights have been infringed by this repository, please contact