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Influence of Optical Defocus on Peripheral Vision
KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.ORCID iD: 0000-0002-4894-7944
KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.ORCID iD: 0000-0001-9172-858X
2011 (English)In: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, Vol. 52, no 1, 318-323 p.Article in journal (Refereed) Published
Abstract [en]

PURPOSE. Peripheral optical corrections are often thought to give few visual benefits beyond improved detection acuity. However, patients with central visual field loss seem to benefit from peripheral correction, and animal studies suggest a role for peripheral vision in the development of myopia. This study was conducted to bridge this gap by systematically studying the sensitivity to optical defocus in a wide range of peripheral visual tasks. METHODS. The spatial frequency threshold for detection and resolution in high and low contrast with stationary and drifting gratings were measured off-axis (20 nasal visual field) in five subjects with a peripheral optical correction that was varied systematically +/- 4 D. RESULTS. All visual tasks, except high-contrast resolution, were sensitive to optical defocus, particularly low-contrast resolution with an increase of up to 0.227 logMAR/D. The two myopic subjects exhibited a very low sensitivity to defocus by negative lenses for low-contrast tasks, whereas all subjects were equally affected by myopic defocus. Contrary to expectations, drifting gratings made little difference overall. CONCLUSIONS. Optical defocus as low as 1 D has a large impact on most peripheral visual tasks, with high-contrast resolution being the exception. Since the everyday visual scenery consists of objects at different contrast levels, it is understandable that persons with central visual field loss are helped by correction of peripheral refractive errors. The asymmetry in sensitivity to peripheral optical defocus in low-contrast tasks that was experienced by the myopic subjects in this study merits further investigation.

Place, publisher, year, edition, pages
2011. Vol. 52, no 1, 318-323 p.
Keyword [en]
visual-acuity, refractive error, resolution acuity, eye growth, thresholds, repeatability, aberrations, myopia
National Category
Medical Laboratory and Measurements Technologies
URN: urn:nbn:se:kth:diva-29719DOI: 10.1167/iovs.10-5623ISI: 000285925000040ScopusID: 2-s2.0-79952221478OAI: diva2:397283
QC 20110214Available from: 2011-02-14 Created: 2011-02-14 Last updated: 2013-03-27Bibliographically approved
In thesis
1. Peripheral Vision: Adaptive Optics and Psychophysics
Open this publication in new window or tab >>Peripheral Vision: Adaptive Optics and Psychophysics
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis is about our peripheral vision. Peripheral vision is poor compared to central vision, due to both neural and optical factors. The optical factors include astigmatism, defocus and higher order aberrations consisting mainly of coma. Neurally, the density of ganglion cells decreases towards the periphery, which limits the sampling density. The questions that this thesis attempts to answer are how much and under which circumstances correction of optical errors can improve peripheral vision. For this, an adaptive optics system has been constructed with a wavefront sensor and a deformable mirror working in closed loop to perform real-time correction of optical errors. To investigate vision, psychophysical routines utilizing Bayesian methods have been evaluated and modified for peripheral vision to handle the presence of aliasing, fixation instability and rapid fatigue.

We found that correcting both refractive errors and higher order aberrations improved peripheral low-contrast resolution acuity. \\

We looked at two specific topics in peripheral vision research in particular: Central visual field loss and myopia development. Persons with central visual field loss have to rely on their remaining peripheral vision, and it is of great interest to understand whether optical correction can offer them any benefits. In a case study on a single subject, we found meaningful improvements in vision with both optimized refractive correction as well as additional benefits with aberration correction. These improvements were larger than for comparable healthy subjects with a similar magnitude of aberrations. When it comes to myopia development, an interesting hypothesis is that peripheral optics affect and guide the emmetropization process. We have found an asymmetric depth of field in the periphery for myopic subjects, caused by their higher order aberrations, and presented a model on how this asymmetry may influence the emmetropization process.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2013. xiii, 72 p.
Trita-FYS, ISSN 0280-316X ; 2013:08
National Category
Other Physics Topics
urn:nbn:se:kth:diva-120077 (URN)978-91-7501-698-6 (ISBN)
Public defence
2013-04-19, Sal FD5, AlbaNova Universitetscentrum, Roslagstullsbacken 21, Stockholm, 13:00 (English)

QC 20130327

Available from: 2013-03-27 Created: 2013-03-27 Last updated: 2013-04-12Bibliographically approved

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Rosén, RobertLundström, LindaUnsbo, Peter
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