• Completed

    Calibration of Eccentric Power Refractor

    Eccentric power refractors need to be calibrated for accommodation and gaze position for individual participants. Calibration however can be time consuming. We look at different conditions in which calibration is necessary or preferable. 


  • Completed

    The Window of Spatial Attention in Reading

    We investigate the dynamics of spatial attention while the eyes move around to gather information.

  • Completed

    Parafoveal Crowding

    Crowding increases with eccentricity, and is most readily observed in the periphery. During natural, active vision however, central vision plays an important role. Measures of critical distance to estimate crowding are difficult in central vision, as these distances are small.

  • Completed
    Hands with pen on street map closeup

    Audio/Tactile BART Station Maps

    This collaborative project between Smith-Kettlewell and the San Francisco LightHouse applies Smartpen-Based audio/tactile graphics tools to improve orientation and wayfinding by travelers with visual disabilities in and around unfamiliar transit stations.

  • Completed

    Tutorials and Reference

    These are tutorials and reference materials I have written on various topics in probability and geometry over the years.

  • Completed
    Mapped scotoma and PRL


    Walker et al (Renninger, Psomadakis, Dang & Fletcher, 2008) suggested a novel method to estimate the monocular scotoma area from perimetry data in macular degeneration based on (i) an optic-disc based estimation of the location of the fovea and (ii) the increase in the receptive field size with eccentricity. Here, Dr Walker and I introduce a new GUI that applies this method to data from the Optos OCT/SLO.

  • Completed

    Assessment of Speechreading with Dual Sensory Loss: Visual and Hearing Impairments

    The purpose of this research study is to test subjects who have various hearing and vision problems on their lipreading, visual and auditory skills in order to understand the relationships between lipreading and visual impairment.

  • Completed

    Micro-Perimetry by Scanning Laser Ophthalmoscope

    We developed software to make the retinal placement of stimuli during micro-perimetry by a scanning laser ophthalmoscope (SLO) independent of involuntary fixational eye movements.

  • Completed

    Motion as a Cue for Attention

    We investigated whether relative motion can serve as a cue for sustained attention.

  • Completed

    Focal Attention and Letter Recognition

    We studied letter recognition in 8 deg eccentricity from the fovea after attracting sustained focal attention to the stimulated location by a cue. Young and elderly healthy subjects, as well as patients with central vision loss participated.

  • Completed

    Reading with the Retinal Periphery

    Typographical features of letters were manipulated in such a way that frequently occurring letter confusions in eccentric viewing happened less frequently.