Yes / Purpose -
Blur adaptation occurs when an observer is exposed to continuous defocus. However, it is unclear whether adaptation requires constant defocus, or whether the effect can still be achieved when the adaptation period is interrupted by short periods of clear vision.
Methods -
The study included 12 emmetropes and 12 myopes. All observers wore full refractive correction throughout the experiment. 1D and 3D of myopic defocus was introduced using spherical convex lenses. An automated system was used to place the blurring lens before the RE for varying periods of blurred and clear vision during adaptation. Participants watched a DVD at 3 m during each 15 min trial. Visual acuity was measured using Test Chart 2000 before and after adaptation.
Results -
Blur adaptation occurs to varying degrees depending on the periods of incremental blur exposure. Significant improvements in defocused visual acuity occur with continuous blur, equal blur and clear periods, as well as for longer blur periods. However, longer clear periods showed reduced adaptation and this trial is significantly different to the other three trials for both defocus levels (p < 0.001). No refractive group differences were observed for neither 1D nor 3D defocus (p = 0.58 and p = 0.19 respectively).
Conclusions -
Intervening periods of clear vision cause minimal disruption to improvements in defocused visual acuity after adaptation, indicating that blur adaptation is a robust phenomenon. However, when the exposure to clear vision exceeds the defocused periods, adaptation is inhibited. This gives insight into the effects of real-world tasks on adaptation to blur. / Ms Kiren A. Khan was supported by a School of Optometry and Vision Science PhD studentship.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/10662 |
| Date | 27 October 2016 |
| Creators | Khan, Kiren A., Cufflin, Matthew P., Mallen, Edward A.H. |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, Accepted manuscript |
| Rights | © 2016 Wiley This is the peer reviewed version of the following article: Khan KA, Cufflin MP and Mallen EAH (2016) The effect of interrupted defocus on blur adaptation. Ophthalmic and Physiological Optics. 36(6): 649-656, which has been published in final form at http://dx.doi.org/10.1111/opo.12323. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving., Unspecified |
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