Projects

  • Fixational and Functional PRL in Central Vision Loss

    Individuals with central vision loss (commonly due to age-related macular degeneration), must use viewing strategies using peripheral vision. Patients often adopt a preferred retinal locus (PRL) for visually guided behavior. While the are clinical measures for estimating the PRL, little is known about use in the real world. Our research seeks to characterize this natural behavior and inform visual rehabilation techniques.

  • 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.

  • Active
    Image of the retina with a centroid target superimposed. The fovea is off-center from the target.

    Fovea Use During Smooth Pursuit

    There is continuing debate as to whether smooth pursuit relies on the foveation of a moving target, especially when the target is compact. Previous studies have shown that gaze is placed on the center-of-mass of a target during saccadic eye movements.

  • Functional Assessment - Book Chapters

    Categorization of visual functioning requires appropriate measurement methods.  Dr. Colenbrander has discussed the principles of functional assessment in several book chapters.

  • Functional Assessment - Contrast Sensitivity

    For eye doctors measuring contrast sensitivity loss during routine eye exams is not a priority, since contrast losses are not disease specific and do not guide treatment decisions. 

  • Functional Assessment - Guidelines and Reports

    Combining his interests in classification and in vision rehabilitation, Dr. Colenbrander has promoted a better understanding of the various aspects of vision loss, their causes, and above all their consequences for the person.

  • Functional Assessment - Reading

    Difficulty reading is the most common complaint of low vision patients.  It is the Activity of Daily Living that is most closely related to visual acuity, but involves many additional factors beyond. 

  • Functional Assessment - Visual Acuity

    Visual acuity is a mainstay for the assessment of “How the EYE functions”. Traditional, non-logarithmic, visual acuity charts, however, are inaccurate for visual acuities worse than 20/100.

  • Functional Assessment - Visual Fields

    Most patients are unaware of their visual field defects and scotomata, be it from AMD, from glaucoma, from RP, or from other causes. 

  • Active

    Go and Nogo Decision Making

    The decision to make or withhold a saccade has been studied extensively using a go-nogo paradigm, but little is known about the decision process underlying pursuit of moving objects. Prevailing models describe pursuit as a feedback system that responds reactively to a moving stimulus.

  • Active
    Plot of finger movement paths over a page of braille text

    Haptic Kinematics of Two-Handed Braille Reading in Blind Adults

    This page (currently under construction) accompanies a work-in-progress poster at the 2020 Eurohaptics meeting.

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