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We used a new method to measure the perceived quality of contrast-enhanced motion video. Patients with impaired vision (n=24) and normally sighted subjects (n=6) adjusted the level of MPEG-based enhancement of 8 videos (4 min each) drawn from 4 categories. They selected the level of enhancement that provided the preferred view of the videos, using a decreasing-step-size staircase procedure. Mos...

Luminance and color information are considered to be processed in parallel systems. The integration of information from these two separate systems is crucial for the visual system to produce a coherent percept. To investigate how luminance and color lights are perceived in time, we measured the perceived duration of light stimuli with and without colors in a paradigm involving simultaneous perc...

BACKGROUND Thyroid hormone has been shown to control retinal cone opsin expression, the protein of color vision, in adult rodents. OBJECTIVES The aim of this study was to evaluate the effect of hypothyroidism on color contrast sensitivity in adult overt hypothyroid patients. METHODS Thirty-eight overt hypothyroid (31 females, 7 males) subjects and 20 euthyroid (16 females, 4 males) controls...

Amblyopia is usually considered to be a deficit in spatial vision. But there is evidence that amblyopes may also suffer specific deficits in motion sensitivity as opposed to losses that can be explained by the known deficits in spatial vision. We measured sensitivity to visual motion in random dot displays for strabismic and anisometropic amblyopic monkeys. We used a wide range of spatial and t...

PURPOSE. One critical concern about using perceptual learning to treat amblyopia is whether training with one particular stimulus and task generalizes to other stimuli and tasks. In the spatial domain, it has been found that the bandwidth of contrast sensitivity improvement is much broader in amblyopes than in normals. Because previous studies suggested the local motion deficits in amblyopia ar...