• methods
  • In addition, applying two-dimensional Bayesian estimation to the final data set showed similar levels of reliability and efficiency across widely disparate and established sampling methods (from classical one-dimensional sampling, such as Ψ or staircase, to more novel multi-dimensional sampling methods, such as quick contrast sensitivity function and Fisher information gain). (frontiersin.org)
  • The results indicated that two-dimensional Bayesian inference of contrast sensitivity function data provides similar estimates across a wide range of sampling methods. (frontiersin.org)
  • When a system's responsivity is a fixed monotonic nonlinear function, thatnonlinearity can be estimated and corrected for, to determine the spectral sensitivity from spectral input-output data via standard linear methods. (wikipedia.org)
  • wavelength
  • It has been established that the maximum spectral sensitivity of the human eye under daylight conditions is at a wavelength of 555 nm, while at night the peak shifts to 507 nm. (wikipedia.org)
  • In sensor systems, where the output is easily quantified, the responsivity can be extended to be wavelength dependent, incorporating the spectral sensitivity. (wikipedia.org)
  • In other contexts, the spectral sensitivity is expressed as the relative response per light energy, rather than per quantum, normalized to a peak value of 1, and a quantum efficiency is used to calibrate the sensitivity at that peak wavelength. (wikipedia.org)
  • logMAR
  • Median differences between Y-VA examinations (repeatability) were 0 LogMAR except between examinations 1 and 2 at the 25% contrast level, where it was 0.3 LogMAR. (diva-portal.org)
  • scotopic
  • Scotopic vision Mesopic vision Candela Purkinje effect Photometry Photosensitive ganglion cell Adaptation (eye) Contrast (vision) Cone cell Pelz, J. (1993). (wikipedia.org)
  • vision
  • Low vision often causes decreased contrast sensitivity as well as reduced resolution, making it more difficult to see low-contrast images on SVD devices. (thefreedictionary.com)
  • Conclusions: The blurred vision caused by exposure to TEA can be documented by measuring contrast sensitivity. (ebscohost.com)
  • Self-reported improvements in color and contrast vision may not correspond to controlled testing. (arvojournals.org)
  • Their sensitivity ranges overlap to provide vision throughout the visible spectrum. (wikipedia.org)
  • Contrast vision may also be greatly reduced. (wikipedia.org)
  • For X-ray films, the spectral sensitivity is chosen to be appropriate to the phosphors that respond to X-rays, rather than being related to human vision. (wikipedia.org)
  • In spite of these complexities, however, the conversion of light energy spectra to the effective stimulus, the excitation of the photopigment, is quite linear, and linear characterizations such as spectral sensitivity are therefore quite useful in describing many properties of color vision. (wikipedia.org)
  • visual system
  • However, there are several techniques that permit not only the evaluation of contrast sensitivity, but also allow researchers to obtain a more complete description of the overall functioning of the visual system (Campbell & Green, 1965). (druglibrary.org)
  • Hering, starting from observations on color appearance, had proposed that the percept of color emerged from spectrally-opponent mechanisms in the visual system that contrasted red vs green and blue vs yellow. (wikipedia.org)
  • estimates
  • This study estimates contrast sensitivity and spatial resolution of two species of benthic sharks, the Port Jackson shark, Heterodontus portusjacksoni , and the brown-banded bamboo shark, Chiloscyllium punctatum, by recording eye movements in response to optokinetic stimuli. (biologists.org)
  • experimental
  • The responses of the rod and cone cells of the retina, however, have a very context-dependent (coupled) nonlinear response, which complicates the analysis of their spectral sensitivities from experimental data. (wikipedia.org)
  • refractive
  • CamBlobs2 is less dependent on viewing distance and refractive error than letter or grating contrast tests and has the potential to allow patient self-assessment of CS outside the doctor's office. (arvojournals.org)
  • describe
  • In visual neuroscience, spectral sensitivity is used to describe the different characteristics of the photopigments in the rod cells and cone cells in the retina of the eye. (wikipedia.org)
  • In photography, film and sensors are often described in terms of their spectral sensitivity, to supplement their characteristic curves that describe their responsivity. (wikipedia.org)
  • stimulus
  • The perceived contrast of a stimulus is sometimes suppressed when another stimulus is presented surrounding it, an effect known as surround suppression (see Figure 1), which is similar to the simultaneous contrast illusion. (wikipedia.org)
  • assess
  • At their first visit, the first 22 subjects also completed a test in which the contrast blobs were of various sizes (13, 9, 6 mm) to assess the effect of angular subtense of blobs on CS. (arvojournals.org)
  • Linear regressions (slope of performance with time) were done to assess whether subjects had the same, improved, or worse contrast sensitivity. (arvojournals.org)
  • conditions
  • The most important variables, in addition to size, that determine visibility under these conditions are the contrast of the target against a background, and whether it is moving or flickering on and off. (druglibrary.org)
  • reduction
  • This is how a reduction of contrast can reduce the clarity of an image - by removing its fine details. (wikipedia.org)
  • A major drawback to application of the algorithm is an inherent reduction in overall image contrast produced by the operation. (wikipedia.org)