| 1. |
- Venkataraman, Abinaya Priya, et al.
(författare)
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Blur adaptation : Contrast sensitivity changes and stimulus extent
- 2015
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Ingår i: Vision Research. - : Elsevier. - 0042-6989 .- 1878-5646. ; 110:PA, s. 100-106
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Tidskriftsartikel (refereegranskat)abstract
- A prolonged exposure to foveal defocus is well known to affect the visual functions in the fovea. However, the effects of peripheral blur adaptation on foveal vision, or vice versa, are still unclear. In this study, we therefore examined the changes in contrast sensitivity function from baseline, following blur adaptation to small as well as laterally extended stimuli in four subjects. The small field stimulus (7.5° visual field) was a 30. min video of forest scenery projected on a screen and the large field stimulus consisted of 7-tiles of the 7.5° stimulus stacked horizontally. Both stimuli were used for adaptation with optical blur (+2.00. D trial lens) as well as for clear control conditions. After small field blur adaptation foveal contrast sensitivity improved in the mid spatial frequency region. However, these changes neither spread to the periphery nor occurred for the large field blur adaptation. To conclude, visual performance after adaptation is dependent on the lateral extent of the adaptation stimulus.
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| 2. |
- Winter, Simon, et al.
(författare)
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Effect of induced transverse chromatic aberration on peripheral vision
- 2015
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Ingår i: Optical Society of America. Journal A. - : Optical Society of America. - 1084-7529 .- 1520-8532. ; 32:10, s. 1764-1771
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Tidskriftsartikel (refereegranskat)abstract
- Transverse chromatic aberration (TCA) is one of the largest optical errors affecting the peripheral image quality in the human eye. However, the effect of chromatic aberrations on our peripheral vision is largely unknown. This study investigates the effect of prism-induced horizontal TCA on vision, in the central as well as in the 20 degrees nasal visual field, for four subjects. Additionally, the magnitude of induced TCA (in minutes of arc) was measured subjectively in the fovea with a Vernier alignment method. During all measurements, the monochromatic optical errors of the eye were compensated for by adaptive optics. The average reduction in foveal grating resolution was about 0.032 +/- 0.005 logMAR/arcmin of TCA (mean +/- std). For peripheral grating detection, the reduction was 0.057 +/- 0.012 logMAR/arcmin. This means that the prismatic effect of highly dispersive spectacles may reduce the ability to detect objects in the peripheral visual field.
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