• Contrast sensitivity function was assessed under photopic conditions. (aston.ac.uk)
  • Adults in their 70s tend to require about 30-60% more contrast to detect high spatial frequencies than adults in their 20s. (wikipedia.org)
  • The accommodating group had better contrast sensitivity under photopic conditions at all spatial frequencies ( P ≤.04). (lww.com)
  • Results: There was no significant reduction in CS at all spatial frequencies by glare stimulus. (kyobobook.co.kr)
  • CS showed a negative correlation with stereopsis under both mesopicand photopic conditions, and a positive correlation with fusional ability at low and intermediate spatial frequencies undermesopic conditions. (kyobobook.co.kr)
  • ΔCS was smaller at intermediate spatial frequencies with better fusional ability, greater at high spatialfrequencies with photophobia, and greater at intermediate spatial frequencies with a higher frequency of exotropia. (kyobobook.co.kr)
  • Photopic contrast sensitivity was significantly better binocularly than monocularly at all spatial frequencies. (aston.ac.uk)
  • The contrast sensitivity was measured in mesopic and photopic background luminances, with glare (G) levels of 0-2 (G0, G1, and G2, respectively) and spatial frequencies at 1.5, 3, 6, 12, and 18 cycles per degree (cpd). (jkos.org)
  • Under low lighting conditions, a reduction in contrast sensitivity for both lenses, particularly at higher spatial frequencies, was noted. (fernandez-vega.com)
  • Contrast sensitivity measurements were performed under photopic conditions (85 cd/m 2 ) with the Visual Contrast Test Sensitivity 6500 chart, allowing for the evaluation of five spatial frequencies with sine wave grating charts: 1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree (cpd). (aboonline.org.br)
  • Purpose: To determine whether contrast sensitivity (CS) can represent photophobia in intermittent exotropia (IXT) by comparingthe CS test with and without glare stimulus, and to analyze the factors of IXT affecting CS. (kyobobook.co.kr)
  • We compared CS undermesopic and photopic conditions, with and without glare. (kyobobook.co.kr)
  • We compared the difference in CS before and after glare (ΔCS) betweenmesopic and photopic conditions, and compared CS with glare between patients with and without photophobia. (kyobobook.co.kr)
  • Halometry was used to measure the angular size of monocular and binocular photopic scotomas arising from a glare source. (aston.ac.uk)
  • However, there was no change in contrast sensitivity at any glare level at 12 and 18 cpd after PTK. (jkos.org)
  • Best corrected visual acuity (BCVA) was measured in photopic (BCVAphotopic) and mesopic (BCVAmesopic) conditions and under glare (BCVAglare). (journalofoptometry.org)
  • Binocular contrast sensitivity function was measured with the Optec 6500 FACT contrast sensitivity chart at distance and at three lighting conditions (85 cd/m2 and 3 cd/m2 with and without glare) in 36 eyes of 18 patients implanted with the AcrySof ReSTOR aspheric SN6AD3 IOL and 40 eyes of 20 patients implanted with the Acri.LISA 366D IOL. (fernandez-vega.com)
  • ISRCTN13894787 ) were assessed using a range of psychophysical measures of visual function, including best corrected visual acuity (BCVA), letter contrast sensitivity (CS), mesopic and photopic CS, mesopic and photopic glare disability (GD), photostress recovery time (PRT), reading performance and subjective visual function, using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). (bmj.com)
  • High spatial frequency refers to higher lines per millimeter or higher cycles per degree of vision. (quickguide.org)
  • In humans and many other animals, photopic vision allows color perception, mediated by cone cells, and a significantly higher visual acuity and temporal resolution than available with scotopic vision. (wikipedia.org)
  • it can occur in 5 minutes for photopic vision but it can take 30 minutes to transition from photopic to scotopic. (wikipedia.org)
  • Adaptation (eye) Candela Cone cell Contrast (vision) Mesopic vision Night vision Purkinje effect Photometry (optics) Photosensitive ganglion cell Scotopic vision Pelz, J. (1993). (wikipedia.org)
  • American Music Teacher (1996, June/July) Dyslexia or Scotopic Sensitivity Syndrome? (irlen.com)
  • It has two modes of vision: photopic vision and scotopic vision. (electrical4u.com)
  • There is also a transition zone between photopic and scotopic vision called mesopic vision. (electrical4u.com)
  • Other luminosity functions include the scotopic sensitivity function and the mesopic sensitivity function. (electrical4u.com)
  • A detector that very closely matches the CIE photopic function is required for accurate photometry. (light-measurement.com)
  • However, fiber photometry also has some limitations, such as low spatial resolution, signal contamination from background fluorescence or movement artifacts, and potential tissue damage or inflammation from fiber implantation. (electrical4u.com)
  • Defocus curves were assessed under photopic and mesopic conditions over a range of +1.50 to -4.00 diopters (D) in 0.50 D steps. (aston.ac.uk)
  • Defocus curve testing showed an extended range of clear vision from +1.00 to -2.50 D defocus, with a significant difference in acuity between photopic conditions and mesopic conditions at -1.50 D defocus only. (aston.ac.uk)
  • Avaliação da sensibilidade ao contraste foi realizada sob condições fotópicas (85 cd/m2) com tabela Visual Contrast Test Sensitivity 6500, permitindo avaliação de cinco frequências espaciais medidas com redes senoidais: 1.5, 3.0, 6.0, 12.0 e 18.0 ciclos por grau de ângulo visual (cpd). (aboonline.org.br)
  • Photopic vision is the vision of the eye under well-lit conditions (luminance levels from 10 to 108 cd/m2). (wikipedia.org)
  • A number of studies have shown that aspherical IOLs perform better compared to conventional spherical ones in terms of contrast sensitivity (CS), particularly under mesopic conditions [ 2 , 3 ]. (hindawi.com)
  • ΔCS was greater at high spatialfrequencies under photopic conditions than under mesopic conditions. (kyobobook.co.kr)
  • Both IOLs provided contrast sensitivity within the normal range in photopic conditions. (fernandez-vega.com)
  • The AcrySof ReSTOR SN6AD3 and Acri.LISA aspheric IOLs provided contrast sensitivity within normal range under photopic conditions and a reduction in contrast sensitivity under mesopic conditions, with no significant differences between the two brands. (fernandez-vega.com)
  • Under a wide range of conditions, sensitivity to chromatic contrast is lower than that for luminance contrast. (visionscience.com)
  • DIN EN 1956, ASTM and MIL Standards exist that describe the general conditions and standard practices for the penetrant test examinations, including the procedures to be followed. (light-measurement.com)
  • When we examined the number of bouts greater than 30 and 60 s in duration, we found a significant difference between the light and dark sides in all light contrast conditions. (researchgate.net)
  • sides in all light contrast conditions. (researchgate.net)
  • The most commonly used luminosity function is the photopic sensitivity function, which models the eye's response under photopic conditions. (electrical4u.com)
  • Outcomes were measured in contrast sensitivity threshold scores among and within groups, from baseline to 1, 3, and 6 months. (aboonline.org.br)
  • Adjustment, yes/no or two-alternative forced-choice psychophysical procedures are selectable for the measurement of threshold sensitivity levels. (visionscience.com)
  • Recent neurophysiological results have clarified some of the neural mechanisms responsible for spatial resolution and demonstrated the inadequacy of the two-point threshold as a measure of spatial mechanisms. (sagepub.com)
  • The images are generated under parametric control to permit a wide variety of published and novel experiments in the detection, masking, discrimination and perception of contrast variations. (visionscience.com)
  • Cones enable color perception and are best in bright (photopic) light. (informit.com)
  • The detector spatial response (angular response) is another important factor and potential error source. (light-measurement.com)
  • The detector's spatial response (angular response) is another important factor and potential error source. (gigahertz-optik.com)
  • Contrast sensitivity, the ability to distinguish the relative difference in luminance of an object from its surrounding or adjacent objects, is a useful measure of visual function. (jkos.org)
  • We compared the contrast sensitivity of GCD2 patients before and after phototherapeutic keratectomy (PTK) to evaluate the perioperative visual function in these patients. (jkos.org)
  • The core function of noninvasive psychophysical testing is the measurement of contrast sensitivity for spatial patterns specified with some mathematical luminance profile and a controlled time course. (visionscience.com)
  • If the detector spatial response does not closely match the true cosine function, significant errors in readings will result. (light-measurement.com)
  • The spectral response of S-cones peak at 420 nm, M-cones at 534 nm, and L-cones at 564 nm, with significant overlap in their spectral response ranges and varying degrees of sensitivity at these range of wavelengths specified by the function m k (λ), k = r, g, b, as depicted in Figure 2.1(a) . (informit.com)
  • where m k (λ) is the wavelength sensitivity function (also known as the color matching function) of the k th cone type or color sensor. (informit.com)
  • Spatial frequency, orientation and contrast are freely selectable. (visionscience.com)
  • The number of lines or bars per millimeter determines spatial frequency , that is, the spacing of lines per unit interval. (quickguide.org)
  • High spatial frequency is therefore accompanied by higher degradation of the quality of image transferred by the lens. (quickguide.org)
  • The X axis represents the number of lines per millimeter (spatial frequency) while the Y axis represents the modulation score. (quickguide.org)
  • As spatial frequency or lines per millimeter increases the MTF value decreases as a thumb rule for any lens. (quickguide.org)
  • Our study demonstrates a circadian rhythm of contrast sensitivity that peaks during the daytime, and that its regulation involves interactions of D4Rs, the clock gene Npas2 , and the clock-controlled gene adenylyl cyclase 1 ( Adcy1 ) in a subset of retinal ganglion cells (RGCs). (jneurosci.org)
  • Targeted disruption of the gene encoding D4Rs reduces the amplitude of the contrast sensitivity rhythm by reducing daytime sensitivity and abolishes the rhythmic expression of Npas2 and Adcy1 mRNA in the ganglion cell layer (GCL) of the retina. (jneurosci.org)
  • Photopic vision is the eye's response at high levels of brightness, such as during daytime or under artificial lighting. (electrical4u.com)
  • The perceived color of light f ( x 1 , x 2 , λ) at spatial location ( x 1 , x 2 ) depends on the distribution of energy in the wavelength λ dimension. (informit.com)
  • therefore, the optic nerve must cross through the retina en route to the brain. (wikipedia.org)
  • [6] In contrast, in the cephalopod retina, the photoreceptors are in front, with processing neurons and capillaries behind them. (wikipedia.org)
  • The challenge in this enterprise was to develop stimuli with sufficient resolution of fine contrast variations to allow measurement of human contrast sensitivity, which can be as low as a 0.2% difference between light and dark regions of the stimulus. (visionscience.com)
  • Inhibitory neurons in the midbrain spatial attention network, called isthmi pars magnocellularis (Imc), control stimulus selection by the sensorimotor and attentional hub, the optic tectum (OT). (nature.com)
  • Their sensitivity ranges overlap to provide vision throughout the visible spectrum. (wikipedia.org)
  • nm) has a luminous efficacy of 683 lm/W. The wavelengths for when a person is in photopic vary with the intensity of light. (wikipedia.org)
  • A still image is a 2D/3D spatial distribution of intensity that is constant with respect to time. (informit.com)
  • A video is a 3D/4D spatio-temporal intensity pattern, i.e., a spatial-intensity pattern that varies with time. (informit.com)
  • Contrast sensitivity comparison between AcrySof ReSTOR and Acri.LISA aspheric intraocular lenses. (fernandez-vega.com)
  • Repetitive spatial patterns are based on sinusoidal, square and ramp luminance profiles in linear, radial, spoke, 2D checkerboard and hexagonal configurations. (visionscience.com)
  • The luminance scale is fully linearizable to 99.9% output contrast (with monitor calibration). (visionscience.com)
  • Contrast and its modulation are controlled by a look-up table animation, which may be split into two or four separate functions (with a corresponding loss in the number of available luminance levels for each independent image). (visionscience.com)
  • They generate spatial opponency in both cones and bipolar cells. (org.es)
  • Optical quality is a subjective construct that can only be described indirectly by objective metrics such as wavefront error measurements and visual quality metrics or functional data like visual acuity and contrast sensitivity. (hindawi.com)
  • Hence, many imaging system design choices and parameters, including spatial and temporal resolution as well as color representation, have been inspired by or selected to imitate the properties of human vision. (informit.com)
  • Several new methods may overcome these problems and provide a valid measure of spatial resolution and a reflection of neural mechanisms. (sagepub.com)
  • The Contrast or modulation ratio is the difference between the brightest part and the darkest part of an image. (quickguide.org)
  • Light sensitivity and some pervasive developmental disorders: autistic disorder, Asperger's disorder. (irlen.com)
  • Adequate illumination of the test object with white light is critical to create good contrast. (light-measurement.com)
  • While in-clinic contrast sensitivity tests give us an idea of the IOL performance in real world, optical bench testing of IOLs is preferable in many ways because it eliminates certain variables like pupil size, lens centration and alignment, light adjustments, accommodation, etc. (quickguide.org)
  • In the high-contrast (∼400 lux) illumination condition, the mean bout length (i.e., duration of one trip on the light or dark side) was significantly longer on the dark side than on the light side. (researchgate.net)
  • By contrast to the above, understanding of the sensory mechanisms controlling acute effects of light on rodent behaviour (light avoidance/aversion and suppression of activity) is currently less complete. (biomedcentral.com)
  • Our results indicate that the contrast sensitivity rhythm is modulated by D4Rs via a signaling pathway that involves NPAS2-mediated circadian regulation of Adcy1 . (jneurosci.org)
  • These results reveal key design principles of the midbrain spatial attention circuit and highlight the critical importance of competitive interactions within Imc for its operation. (nature.com)
  • By definition the MTF is a measure of the ability of lens to transfer contrast at a particular resolution from the object to the image. (quickguide.org)
  • Thought MTF is the measure of the contrast that the optics of the lens system offer, yet resolution and contrast are closely linked. (quickguide.org)
  • A computational-observer model of spatial contrast sensitivity: Effects of wave-front-based optics, cone-mosaic structure, and inference engine. (neurotree.org)
  • Therefore, my work is centered on optical technologies that can reveal and monitor pathology with ever increasing sensitivity and detail, even revealing cellular and sub-cellular structural and functional changes. (stanford.edu)
  • En face OCT reflectance images which accompany OCTA studies offer a glimpse of the macrophage-like cellular activity above the retinal surface which responds to systemically instigated vascular events below. (stanford.edu)
  • For neurons involved in spatial selection, a core characteristic that impacts both these functions is their spatial receptive field (RF), defined as the subset of the spatial locations that a neuron responds to selectively. (nature.com)
  • The difference between the brightest and darkest regions diminishes and contrast is lost. (quickguide.org)
  • This utility approach to signal detection theory clarifies otherwise enigmatic influences of perceptual uncertainty on measures of decision-making performance (accuracy and optimality) and on behavior (an inverse relationship between bias magnitude and sensitivity optimizes utility). (sagepub.com)
  • A computational observer model of spatial contrast sensitivity: Effects of photocurrent encoding, fixational eye movements, and inference engine. (neurotree.org)
  • Expertise in the spatial pattern and also rate regarding decrease across the variety coming from typical aging for you to Alzheimer disease provides useful data regarding discovering earlier condition as well as checking treatment effects from different periods associated with illness further advancement. (vdacsignaling.com)