Elimination of the color discrimination impairment along the blue-yellow axis in patients with hypothyroidism after treatment with levothyroxine as assessed by the Farnsworth-Munsell 100 hue test.

Our previous study has shown that individuals with untreated hypothyroidism display significantly higher partial error scores ( ) along the blue-yellow axis compared to the red-green axis than normal individuals using the Farnsworth-Munsell 100 hue test [J. Opt. Soc.

Visual noise effect on reading in three developmental disorders: ASD, ADHD, and DD.

Background And Aims: Developmental disorders such as Autism Spectrum Disorder (ASD), Attention Deficit Hyperactivity Disorder (ADHD), and Developmental Dyslexia (DD) are reported to have more visual problems, oral language difficulties, and diminished reading skills in addition to their different diagnostic features. Moreover, these conditions also have increased internal noise and probably an impaired ability of external noise filtering. The aim of the present study was to compare the reading performance of these groups in the presence of external visual noise which disrupts the automatic reading processes through the degradation of letters.

The Effect of Induced Intraocular Stray Light on Recognition Thresholds for Pseudo-High-Pass Filtered Letters.

Purpose: The Moorfields Acuity Chart (MAC)-comprising pseudo-high-pass filtered "vanishing optotype" (VO) letters-is more sensitive to functional visual loss in age-related macular degeneration (AMD) compared to conventional letter charts. It is currently unknown the degree to which MAC acuity is affected by optical factors such as cataract. This is important to know when determining whether an individual's vision loss owes more to neural or optical factors.

Resolution acuity and spatial summation of chromatic mechanisms in the peripheral retina.

Green stimuli are more difficult to detect than red stimuli in the retinal periphery, as reported previously. We examined the spatial characteristics of chromatic mechanisms using stimuli, modulated from an achromatic background to each pole of the "red-green" cardinal axis in DKL space at 20 deg eccentricity. The "blue-yellow" cardinal axis was also studied for comparison.

Color discrimination assessment in patients with hypothyroidism using the Farnsworth-Munsell 100 hue test.

There is evidence in the literature that hypofunction of the thyroid gland (hypothyroidism) affects color vision in rodents by influencing the production of the visual pigment opsin. The effect of hypothyroidism on color vision in humans has not been examined in any great detail. In this cross-sectional study we evaluated color discrimination using the Farnsworth-Munsell 100 hue test (FM-100 test) in 25 individuals with pre-treatment hypothyroidism (mean age ${38}\;{\pm }\;{9}.

Effect of extending grating length and width on human visually evoked potentials.

Visually evoked potentials (VEPs) were elicited by Gabor gratings with different lengths and widths at three spatial frequencies (SFs): low, 1.45 c/deg, medium, 2.9 c/deg and high, 5.

Sensitivity to stimulus onset and offset in the S-cone pathway.

Previous work [Vassilev, capital A, Cyrillic., Mihaylova, M., Racheva, K.

Spatial summation of S-cone ON and OFF signals: effects of retinal eccentricity.

We studied spatial summation for S-cone ON and OFF signals as a function of retinal eccentricity in human subjects. S-cone isolation was obtained by the two-colour threshold method of Stiles, modified by adding blue light to the yellow background. Test stimuli were blue light increments or decrements within a circular area of variable size.