Role of parafovea in blur perception published in Vision Research
The blur experienced by our visual system is not uniform across the visual field. Additionally, lens designs with variable power profile such as contact lenses used in presbyopia correction and to control myopia progression create variable blur from the fovea to the periphery. We studied the perceived neutral focus with images of different angular subtense (from 4° to 20°) and found that the amount of blur, for which focus is perceived as neutral, increases with stimulus size. We also studied the changes in central perceived neutral focus after adaptation to images with similar magnitude of optical blur across the image or varying blur from center to the periphery. Altering the blur in the periphery had little or no effect on the shift of perceived neutral focus following adaptation to normal/blurred central images. These perceptual outcomes should be considered while designing bifocal optical solutions for myopia or presbyopia.
The study is a result of collaborative work between the Department of Applied Physics, KTH, Royal Institute of Technology and VioBio Lab, Instituto de Optica CSIC, in the context of Marie Curie ITN Opal.
The results are published in Vision Research: A. Venkatamaran, A. Radhakrishan, C. Dorronsoro, L. Lundström & S. Marcos, “Role of Parafovea in blur perception”, Vision Research 138, 59-65 (2017).
Full article here.