The variability of color-selective neurons in human visual cortex is considered more diverse than cone-opponent mechanisms. We addressed this issue by deriving histograms of hue-selective voxels measured using fMRI with a novel stimulation paradigm, where the stimulus hue changed continuously. Despite the large between-subject difference in hue-selective histograms, individual voxels exhibited ...

BACKGROUND To report the first described case of combined haemolytic and acute angle closure glaucoma secondary to spontaneous intraocular haemorrhages in a patient on excessive anticoagulation. To the best of our knowledge, this is the first case reported in the literature presenting with raised intraocular pressure due to both mechanisms. CASE DESCRIPTION A 90-year-old woman presented with ...

BACKGROUND We sought to investigate the association between blood pressure levels and prevalence of acquired color vision impairment in middle-aged Japanese men. METHODS Participants underwent color vision testing, ophthalmological examination, standardized interview, physical record examination, and venous blood examination. Cardiovascular disease risk factors were determined based on blood ...

Traditional trichromatic theories of color vision conclude that color perception is not possible under scotopic illumination in which only one type of photoreceptor, rods, is active. The current study demonstrates the existence of scotopic color perception and indicates that perceived hue is influenced by spatial context and top-down processes of color perception. Experiment 1 required observer...

In this paper, we proposed the digital watermarking for a color image. In order to embed watermark signal, we consider the characteristics of HVS(human visual system) and focus on the relatively insensitive components of a color image. In YCrCb color space, Y component is achromatic luminance and both Cr and Cb components are chromatic color. At the Cr-Cb chrominance plane, an angle of a pixel ...

Panel tests of color vision (eg FM100-Hue test) lack a common quantitative method for the scoring of cap arrangements. We describe a scoring method applicable to all panel tests that makes use of a novel technique to analyze test cap data, namely the calculation of a moment of inertia from the Color Difference Vectors (CDVs) of any arrangement pattern. Using the Farnsworth D-15 panel, as an exa...

PURPOSE The blue-sensitive pathway in normal subjects and in patients with primary open-angle glaucoma (POAG) was tested with the pattern visual evoked potential (VEP) method under selective adaptation. METHODS Recording of pattern-onset VEP in response to blue (460-nm) stripes (0.88 c/deg) presented either without or with a bright yellow (570-nm) adaptation light (Maxwellian view, 33 degree ...