Functional aspects of blur adaptation in human vision. A study of the mechanism of blur adaptation in human vision - its origin and scope evidenced using subjective and objective procedures.

Sensory adaptation to blur improves visual acuity under defocused conditions. This phenomenon has been successfully demonstrated using subjective measures of acuity and is known as blur adaptation. This study investigates aspects of the mechanism of blur adaptation in human vision using subjective and objective methods. Parafoveal visual acuity measured under defocused conditions demonstrates that blur adaptation is not limited to the fovea. The presence of the adaptive mechanism in the parafovea also suggests that the neural compensation that takes places under defocused conditions acts across a spatial range and is not limited to specific frequency bands. An evaluation of the contrast sensitivity function under defocus provides further evidence. Electrophysiological methods measure the effect of blur adaptation at the retina and at the visual cortex to provide objective evidence for the presence of the blur adaptation mechanism. Finally enhanced-depth imaging optical coherence tomography examines whether a period of prolonged defocus triggers any short-term changes in choroidal thickness in a similar manner to that reported in animal emmetropisation.

Grantor dc:publisher.institution

University of Bradford

Year dc:date.issued

2014

Author dc:creator

• Mankowska, Aleksandra

Advisors dc:contributor.advisor

• Mallen, Edward A.H.
• McKeefry, Declan J.

• Blur adaptation
• Parafovea
• Visual acuity
• Electroretinogram
• Visual evoked potential
• Optical coherence tomography

Statement dc:rights

• <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>.

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10454/6329

OAI identifier oai:identifier

oai:bradscholars.brad.ac.uk:10454/6329