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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 is typically expressed as the reciprocal of the threshold contrast for detection of a given pattern (i.e., 1 ÷ contrast threshold). [15] 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.
Minimum resolvable contrast (MRC) is a subjective measure of a visible spectrum sensor’s or camera's sensitivity and ability to resolve data.A snapshot image of a series of three bar targets of selected spatial frequencies and various contrast coatings captured by the unit under test (UUT) is used to determine the MRC of the UUT, i.e. the visible spectrum camera or sensor.
Amsler's grid test - to locate scotomas on the visual field of the individual; Colour sensitivity test - to assess the function of the Optic nerve; Contrast sensitivity test - to assess the function of rods photoreceptors; Visual field test - to know the extent of the individual's field that is sensitive
contrast ratio = antilog (2.0 — 0.3) = antilog (1.7) = 50 Therefore contrast ratio = 50 : 1 (50 to 1). When applied to the negative film version of the same test card, the maximum density is 1.30 although the minimum density remains at 0.30. The contrast ratio of the negative is therefore as follows:
The "luminance contrast" is the ratio between the higher luminance, L H, and the lower luminance, L L, that define the feature to be detected.This ratio, often called contrast ratio, CR, (actually being a luminance ratio), is often used for high luminances and for specification of the contrast of electronic visual display devices.
From Wikipedia, the free encyclopedia. Redirect page. Redirect to: Contrast (vision)#Contrast sensitivity; Retrieved from " ...
Residual refraction cylinder (≤ 0.25 D) was 81.8% for the Contoura Vision group and 50% for the SMILE group (P < .001). Contrast sensitivity (6 cycles/degree) was 7.2 ± 1.01 in the Contoura Vision group and 6.20 ± 1.52 in the SMILE group.