Temporary Tritanopia: Effects of cataract surgery on color

2019 ◽  
Vol 2019 (1) ◽  
pp. 201-206
Author(s):  
John J. McCann ◽  
Mary A. McCann

This pilot study made a wide variety of visual measurements before, during, and after bilateral cataract surgery. This article describes the changes in color discrimination and color appearance resulting from cataract implants. It used the F-M 100 Hue Test, color matching of real scenes, and color-balance titration measurements. The pre-surgery data indicated that the previously normal color observers had severe tritanopic anomalies. Lens replacement restored normal color vision.

2009 ◽  
Vol 26 (1) ◽  
pp. 133-145 ◽  
Author(s):  
IGOR JURICEVIC ◽  
MICHAEL A. WEBSTER

AbstractModern accounts of color appearance differ in whether they assume that the perceptual primaries (e.g., white and the unique hues of red, green, blue, and yellow) correspond to unique states determined by the spectral sensitivities of the observer or by the spectral statistics of the environment. We examined the interaction between observers and their environments by asking how color perception should vary if appearance depends on fixed responses in a set of color channels, when the sensitivities of these channels are adapted in plausible ways to different environments. Adaptation was modeled as gain changes in the cones and in multiple postreceptoral channels tuned to different directions in color–luminance space. Gains were adjusted so that the average channel responses were equated across two environments or for the same environment during different seasons, based on sets of natural outdoor scenes (Webster et al., 2007). Because of adaptation, even observers with a shared underlying physiology should perceive color in significantly and systematically different ways when they are exposed to and thus adapted by different contexts. These include differences in achromatic settings (owing to variations in the average chromaticity of locations) and differences in perceived hue (because of differences in scene contrasts). Modeling these changes provides a way of simulating how colors might be experienced by individuals in different color environments and provides a measure of how much color appearance might be modulated for a given observer by variations in the environment.


2016 ◽  
Vol 36 (9) ◽  
pp. 0933001
Author(s):  
黄敏 Huang Min ◽  
史春洁 Shi Chunjie ◽  
李泽阳 Li Zeyang ◽  
刘浩学 Liu Haoxue

2019 ◽  
Vol 2019 (1) ◽  
pp. 320-325 ◽  
Author(s):  
Wenyu Bao ◽  
Minchen Wei

Great efforts have been made to develop color appearance models to predict color appearance of stimuli under various viewing conditions. CIECAM02, the most widely used color appearance model, and many other color appearance models were all developed based on corresponding color datasets, including LUTCHI data. Though the effect of adapting light level on color appearance, which is known as "Hunt Effect", is well known, most of the corresponding color datasets were collected within a limited range of light levels (i.e., below 700 cd/m2), which was much lower than that under daylight. A recent study investigating color preference of an artwork under various light levels from 20 to 15000 lx suggested that the existing color appearance models may not accurately characterize the color appearance of stimuli under extremely high light levels, based on the assumption that the same preference judgements were due to the same color appearance. This article reports a psychophysical study, which was designed to directly collect corresponding colors under two light levels— 100 and 3000 cd/m2 (i.e., ≈ 314 and 9420 lx). Human observers completed haploscopic color matching for four color stimuli (i.e., red, green, blue, and yellow) under the two light levels at 2700 or 6500 K. Though the Hunt Effect was supported by the results, CIECAM02 was found to have large errors under the extremely high light levels, especially when the CCT was low.


Author(s):  
Sheida Anbari ◽  
Hamid Reza Hamidi ◽  
Shokoh Kermanshahani

Color blindness has important effects on people’s daily activities, since most activities require a discernment between colors. It is very important for engineers and designers to understand how colorblind people perceive colors. Therefore, many methods have been proposed to simulate color perception of people affected by Dichromacy and anomalous Trichromacy. However, the simulation results rarely have been evaluated with the reports of concerned individuals. In first study, we tried to simulate the color perception of people with different types (red and green) and different degrees of color blindness. Different degrees of red-green deficiency is simulated on the 24-plates brand of the Ishihara color vision test kit. Then simulated plates were tested on people with normal color vision. The results show that the simulation performance is better in the case of high degrees of red-green deficiency. There is also a clear difference between the assessment of female and male volunteers. In another study, the perception of the color of people with blue-yellow blindness is also considered. The proposed blue-yellow blind simulation is compared with the result of another research project. The results show that the color perception of individuals with different degrees of blue-yellow blindness can be reconstructed with a reasonable accuracy.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Feng Zhang ◽  
Jin-Hua Wang ◽  
Mei-Sheng Zhao

Abstract Background The purpose of the study was to investigate whether dynamic monocyte chemoattractant protein-1 (MCP-1) level might be as predictors of perceived pain during the first and second phacoemulsification eye surgeries in patients with bilateral cataract. Methods Consecutive bilateral cataract patients undergoing bilateral sequential phacoemulsification were retrospectively enrolled. Patients’ preoperative anxiety score and intraoperative pain score were registered. Aqueous humor samples were obtained during surgery. MCP-1 level in the aqueous humor was measured by enzyme linked immunosorbent assay (Elisa). Patients were assigned to seven subgroups based on the interval between first-eye and second-eye cataract surgery. Comparisons were performed for a subjective sensation and MCP-1 levels among different subgroups. Results pain score during second-eye surgery was significantly higher than during first-eye surgery. Whereas there was no statistical difference in anxiety score between both surgeries. Result from subgroups comparison showed that the visual analog scale (VAS) pain score was statistically greater in 1-group and 6-group during the second eye surgery. Anxiety score did not statistically differ in subgroups. Additionally, the second-eye MCP-1 level was significantly higher at week 1and 6 intervals. Preoperative MCP-1 level was positively correlated with perceiving pain score during both surgeries. Conclusions MCP-1 level in aqueous humor significantly correlated with perceived pain during cataract surgery. Dynamic MCP-1 level could function as predictors of perceived pain during the first and second phacoemulsification eye surgeries in patients with bilateral cataract, which might support clinicians in treatment optimization and clinical decision-making.


2013 ◽  
Vol 26 (2) ◽  
pp. 307-313 ◽  
Author(s):  
Kien Gia To ◽  
Lynn B. Meuleners ◽  
Michelle L. Fraser ◽  
Dat Van Duong ◽  
Dung Van Do ◽  
...  

ABSTRACTBackground:Depression is common among older populations with cataract. However, the impact of cataract surgery on depression in both developed and developing countries remains unclear. The aim of this study is to determine the impact of cataract surgery on depressive symptoms and to examine the association between objective visual measures and change in depressive symptoms after surgery among a Vietnamese population in Ho Chi Minh City.Methods:A cohort of older patients with bilateral cataract were assessed the week before and one to three months after first eye surgery only or first- and second-eye cataract surgeries. Visual measures including visual acuity, contrast sensitivity, and stereopsis were obtained. Depressive symptoms were assessed using the 20-item Center for Epidemiological Studies-Depression Scale (CES-D). Descriptive analyses and a generalized estimating equations (GEE) analysis were undertaken to determine the impact of cataract surgery on depressive symptoms.Results:Four hundred and thirteen participants were recruited into the study before cataract surgery. Two hundred and forty-seven completed the follow-up assessment after surgery. There was a significant decrease (improvement) of one point in the depressive symptoms score (p = 0.04) after cataract surgery, after accounting for potential confounding factors. In addition, females reported a significantly greater decrease (improvement) of two points in depressive symptom scores (p = 0.01), compared to males. However, contrast sensitivity, visual acuity, and stereopsis were not significantly associated with change in depressive symptoms scores. First-eye cataract surgery or both-eye cataract surgery did not modify the change in depressive symptoms score.Conclusion:There was a small but significant improvement in depressive symptoms score after cataract surgery for an older population in Vietnam.


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