Search results
Results from the WOW.Com Content Network
Contrast sensitivity is typically expressed as the reciprocal of the threshold contrast for detection of a given pattern (i.e., 1 ÷ contrast threshold). [16] Using the results of a contrast sensitivity exam, a contrast sensitivity curve can be plotted, with spatial frequency on the horizontal, and contrast threshold on the vertical axis.
Contrast is a feature of visual stimuli that characterizes the difference in brightness between dark and light regions of an image. Perception of contrast is affected by the temporal frequency and spatial frequency properties of a stimulus, and the sensitivity to contrast in sine wave stimuli is characterized by the contrast sensitivity function.
It is especially vital to assess a child's contrast sensitivity at a young age in order to determine the distance and accuracy with the child can distinguish facial features. A very popular test designed specifically for this reason is the "Hiding Heidi Low Contrast Face Pictures" test (which the LEA Vision Test System produces a version of.)
Contrast sensitivity. Visual acuity. A practical measure of binocularity is the binocular summation ratio BSR, which is the ratio of binocular contrast sensitivity to the contrast sensitivity of the better eye. [3] = /
Adults in their 70s tend to require about 30–60% more contrast to detect high spatial frequencies than adults in their 20s. [ 3 ] The human eye uses scotopic vision under low-light conditions (luminance level 10 −6 to 10 −3.5 cd/m 2 ), and mesopic vision in intermediate conditions (luminance level 10 −3 to 10 0.5 cd/m 2 ).
A person's contrast sensitivity function is contrast sensitivity as a function of spatial frequency. Normally, peak contrast sensitivity is at about four cycles per degree of visual angle. At higher spatial frequencies, comprising finer and finer lines, contrast sensitivity decreases, until at about forty cycles per degree even the brightest of ...
Log-log plot of spatial contrast sensitivity functions for luminance and chromatic contrast [improve caption] The neurological conversion of color from LMS color space to the opponent process is believed to take place mostly in the lateral geniculate nucleus (LGN) of the thalamus, though it may also take place in the retina bipolar cells.
The De Vries–Rose law [1] or Rose–de Vries law [2] is a principle of vision science named after Hessel de Vries [3] and Albert Rose. [4] De Vries discovered it in 1943 from considerations of quantum efficiency, and Rose developed the idea substantially a few years later.