Contrast Sensitivity

Multifocal intraocular lenses and retinal diseases

“…After 40 years of age, there were losses at all spatial frequencies Tulunay-Keesey et al 1988 [ 14 ] 63 adults (13–67 years of age) CS at spatial frequencies of 0.5, 1, 2, 3, 4, 6, 8, and 12 cpd and temporal frequencies of 0, 1, 5, and 15 Hz Sensitivity for low spatial frequencies modulated at 0 to 15 Hz was not affected by age, but a progressive age-related elevation of threshold was found for combinations of high spatial and temporal frequencies Crassini et al 1988 [ 15 ] 8 young (average age 20.4 years) and 8 elderly (average age 64.4 years) subjects CS (central an 10 deg temporally) at 0.2, 0.8, 2.0, and 5.0 cpd Young observers had better contrast sensitivities than older observers but only at higher spatial frequencies (2.0 and 5.0 cpd) Sloane et al 1988 [ 16 ] 12 young (19–35 years) and 11 older (68–89 years) subjects CS as a function of target luminance at 0.5, 2, 4, and 8 cpd When gratings were flickered at 0.5 Hz, functions for older adults were displaced downward on the sensitivity axis across all luminance levels, and the slopes of these functions were steeper than those for younger adults, suggesting that optical mechanisms alone cannot account for the vision loss in older adults. Higgins et al 1988 [ 17 ] 50 subjects in five age groups (20–29, 30–39, 40–49, 50–59, 60–69 years) CS at nine spatial frequencies from 0.75 to 16 cpd Decline in sensitivity with age at all spatial frequencies Elliot 1987 [ 18 ] 16 young (mean age 21.5 ± 2.7 years) and 16 older (mean age 72 ± 4.3 years) subjects CS at 1, 2, 4, 10.6, and 16.5 cpd Lower contrast sensitivity at medium (4 cpd) and high (10.6, 16.5 cpd) spatial frequencies in older group Yates et al 1987 [ 19 ] 103 adults (21–40 years of age) CS at 1, 2, 4, 8, 12, 16, 20, and 24 cpd The age-related decrease in CS was found only at 16 cpd Ross et al 1985 [ 20 ] 17 young (aged 20–30 years) and 53 older (aged 50–87 years) subjects CS at 0.4, 0.95, 2.88, 6.73, 12.70, and 19.23 cpd Lower performance in older group compared to younger group at all spatial frequencies In the older group, linear decline in CS with age for medium and high spatial frequencies Morrison and McGrath 1985 [ 21 ] 45 observers (including 4 elderly) CS 8–40 cpd (10–15 different frequencies within this range) With increasing age, CS remained steady until the sixth decade when they declined …”

Classification of reticular pattern and streaks in dermoscopic images based on texture analysis

“…19,20 In fact, one of the greatest challenges in classification is the higher inter-and intraindividual variability, due to the limited capacity of the human eye (contrast sensitivity, wavelength sensitivity, orientation discrimination, etc.). [21][22][23] The pigmented network or reticular pattern and streaks are important diagnostic clues, representing a dermoscopic hallmark of melanocytic lesions, which is independent of their biologic behavior. 24 The reticular pattern appears as a grid of thin brown lines over a diffuse light-brown background.…”