Red-green Colour Blindness Research Articles

Multifunctional human visual pathway-replicated hardware based on 2D materials

Artificial visual system empowered by 2D materials-based hardware simulates the functionalities of the human visual system, leading the forefront of artificial intelligence vision. However, retina-mimicked hardware that has not yet fully emulated the neural circuits of visual pathways is restricted from realizing more complex and special functions. In this work, we proposed a human visual pathway-replicated hardware that consists of crossbar arrays with split floating gate 2D tungsten diselenide (WSe2) unit devices that simulate the retina and visual cortex, and related connective peripheral circuits that replicate connectomics between the retina and visual cortex. This hardware experimentally displays advanced multi-functions of red–green color-blindness processing, low-power shape recognition, and self-driven motion tracking, promoting the development of machine vision, driverless technology, brain–computer interfaces, and intelligent robotics.

Impact of EnChroma glasses on red-green color vision deficiency: a prospective study.

Impact of EnChroma glasses on red-green color vision deficiency: a prospective study.

Genetic analysis of a Chinese pedigree affected with Branchio-oculo-facial syndrome and a literature review

To explore the genetic etiology of a Chinese pedigree affected with Branchio-oculo-facial syndrome (BOFS) and summarize the prenatal phenotype of BOFS patients. A pedigree with BOFS which had presented at the Genetics and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University in December 2021 was selected as the study subject. Clinical data of the pedigree was collected. The fetus was subjected to routine prenatal ultrasound scan. Trio-whole exome sequencing (trio-WES) was carried out for the fetus and its parents, and candidate variant was verified by Sanger sequencing. Relevant literature was searched from the database to summarize the prenatal phenotype of BOFS patients. Ultrasound exam suggested the fetus had cleft lip and palate. Its father had presented with high palatal arch, prematurely grayed hair, occult cleft lip, congenital preauricular fistula, red-green color blindness and unilateral renal agenesis. Its grandfather also had high palatal arch, prematurely gray hair, protruding ears, congenital preauricular fistula and hearing disorders. Trio-WES revealed that the fetus and its father had both harbored a heterozygous c.890-1G>A variant of the TFAP2A gene. The same variant was not found in its mother. Sanger sequencing confirmed that its grandfather had also harbored the same variant. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as likely pathogenic (PVS1+PM2_Supporting). Combined with 36 similar cases retrieved from the literature, the prenatal phenotypes of BOFS patients had included growth restriction (25/37), renal abnormalities (10/37), cleft lip and palate (5/37) and oligohydramnios (5/37). The c.890-1G>A variant of the TFAP2A gene probably underlay the pathogenesis of BOFS in this pedigree. Discovery of the novel variant has enriched the mutational spectrum of the TFAP2A gene. The common prenatal phenotypes of BOFS have included growth restriction, renal abnormalities, cleft lip and palate and oligohydramnios. Delineation of the intrauterine phenotype of BOFS may facilitate its prenatal diagnosis, clinical diagnosis, treatment and genetic counseling.

Evaluation of contrast sensitivity in patients with congenital red-green color vision deficiency.

To evaluate mesopic and photopic contrast sensitivity in patients with congenital red-green color vision deficiency regarding with and without glare conditions and to compare these findings with age- and gender-matched healthy controls with normal color vision. Patients with congenital red-green color vision deficiency and age- and gender-matched healthy controls were included in this cross-sectional comparative study. Contrast sensitivity measurements were taken from all subjects in 4 different conditions; binocular mesopic-without glare, mesopic-with glare, photopic-without glare, photopic-with glare, and the results were compared. Twenty one patients with color vision deficiency (13 deuteranopic, 8 protanopic) and 22 age- and gender-matched healthy controls were included in the study. The mean age was 35.2 ± 13.5years in the protan group, 30.6 ± 7.7years in the deutan group, 32.0 ± 8.8years in the control group, and there was no significant difference in age between the groups (P > 0.05). The mean mesopic and photopic contrast sensitivity values of the groups at all spatial frequencies (1.5, 3, 6, 12, 18cpd) were not statistically significant when evaluated by the multifactor repeated measures test of ANOVA to evaluate the effect of light conditions (with and without glare) (P > .05). Mesopic and photopic contrast sensitivity values of patients with congenital red-green color vision deficiency were similar to healthy controls regarding with and without glare conditions.

Evaluation of the Efficacy of Enchroma Filters for Correcting Color Vision Impairment

Objective: This study examined the effectiveness of Enchroma Cx-14 filters on individuals with Red-Green color vision deficiency (CVD). Methods: ColorDx and the Farnsworth-Munsell (FM) 100-Hue test were used to assess subjective reactions to Enchroma. The ColorDx and FM, 100 Hue test error scores were computed and contrasted using Placebo (untinted glasses) and Enchroma CX-14, red, and green filters. Results: The findings demonstrated that while enchroma filters improved the mistake score in only two patients, they had no discernible impact on any CVD subject's performance. In one protan participant and all deutan individuals, colour discrimination was greatly enhanced by the red filter. Green filters and Enchroma did not raise mean error scores. Conclusion: Enchroma filters had limited effectiveness in improving color perception for individuals with Red-Green CVD.

The construction of genetics teaching resources related to colour blindness and their application in genetics teaching.

Red-green colour blindness is a classic example for the teaching of X-linked recessive inheritance in genetics course. However, there are lots of types of color vision deficiencies besides red-green colour blindness. Different color vision deficiencies caused by different genes may have different modes of inheritance. In recent years, many research achievements on colour blindness have been made. These achievements could be used as teaching resources in genetics course. Here, we summarize the construction of genetics teaching resources related to colour blindness and their application in genetics teaching in several chapters such as introduction, cellular and molecular basis of genetics, sex-linked inheritance, chromosomal aberration, gene mutation and advances in genetics. Teacher could use the resources in class or after class with different teaching methods such as questioning teaching method and task method. It may expand students' academic horizons and inspire students' interest in genetics besides grasping basic genetic knowledge.

Validation of a New Digital and Automated Color Perception Test.

Although color vision deficiencies are very prevalent, there are no ideal methods for assessing color vision in all environments. We compared a new digital and automated method that quantifies color perception for the three protan, deutan, and tritan axes with two of the most commonly used color tests in daily practice: the Ishihara 38 plates test and the Farnsworth-Munsell 100-Hue test. One hundred patients underwent a triple examination composed of the new DIVE Color Test, the Ishihara test, and the Farnsworth-Munsell 100-Hue test. The DIVE Color Test was performed twice in forty participants to assess its repeatability. In the trichromatic group, the mean age stood at 20.57 ± 9.22 years compared with 25.99 ± 15.86 years in the dyschromatic group. The DIVE and Ishihara tests exhibited excellent agreement in identifying participants with color deficiency (Cohen's kappa = 1.00), while it was 0.81 when comparing DIVE and Farnsworth. The correlation between the global perception values of Farnsworth (TES) and DIVE (GCS) was 0.80. The repeatability of the DIVE Color Test was high according to Bland-Altman analysis with an intraclass correlation coefficient of 0.83. According to Ishihara, the DIVE Color Test proved to be an effective and reproducible tool for red-green color vision deficiency detection, capable of determining the severity of the defect in each of the three axes faster and more accurately than both Ishihara and Farnsworth.

Dyschromatopsia: a comprehensive analysis of mechanisms and cutting-edge treatments for color vision deficiency.

Color blindness is a retinal disease that mainly manifests as a color vision disorder, characterized by achromatopsia, red-green color blindness, and blue-yellow color blindness. With the development of technology and progress in theory, extensive research has been conducted on the genetic basis of color blindness, and various approaches have been explored for its treatment. This article aims to provide a comprehensive review of recent advances in understanding the pathological mechanism, clinical symptoms, and treatment options for color blindness. Additionally, we discuss the various treatment approaches that have been developed to address color blindness, including gene therapy, pharmacological interventions, and visual aids. Furthermore, we highlight the promising results from clinical trials of these treatments, as well as the ongoing challenges that must be addressed to achieve effective and long-lasting therapeutic outcomes. Overall, this review provides valuable insights into the current state of research on color blindness, with the intention of informing further investigation and development of effective treatments for this disease.

Comparison of Two Printed Pseudoisochromatic Tests for Color Vision Assessment.

The Waggoner PIP24 is a pseudoisochromatic test with a pattern similar to the Ishihara test. This study determined that the W-PIP24 can be used clinically to yield screening results (or sensitivity and specificity) comparable with the Ishihara. This study aimed to determine whether the W-PIP24 is equivalent to the Ishihara 38 edition pseudoisochromatic test in detecting red-green color vision defects. Also, the performance of each plate of the W-PIP24 in detecting the color vision defects relative to the Ishihara test was determined. Sixty-three individuals with congenital red-green color vision defects and 57 with normal trichromacy were recruited. Participants were tested with both the Ishihara and W-PIP24. The first-order agreement coefficients were calculated for the Ishihara and W-PIP24. The results were also analyzed using specificity, sensitivity, efficiency, and predictive pass and fail values. The agreement between the W-PIP24 and Ishihara test using the recommended criterion of using all plates was perfect. The sensitivity, specificity, predictive pass, and predictive fail were 1.00 (95% confidence interval, 0.94 to 1.00). This study showed that the W-PIP24 using a failure criterion of three or more errors on screening plates 1 to 15 is equivalent to the Ishihara test while screening for red-green color vision deficiency using a failure criterion of three or more errors on screening plates 1 to 17 of the Ishihara 38 edition.

Prevalence of Congenital Color Vision Deficiency in Southern Taiwan and Detection of Female Carriers by Visual Pigment Gene Analysis.

This study aimed to investigate the prevalence of color vision deficiencies (CVDs) and determine whether carriers could be detected by analyzing the visual pigment genes. Materials and Methods: The data of students who underwent routine CVD screening using the Ishihara color test in Kaohsiung, Southern Taiwan were analyzed. Furthermore, the DNA samples of 80 randomly selected females and four obligate carriers were analyzed. The most upstream genes, downstream genes, and the most downstream genes in the red/green pigment gene arrays were amplified separately using polymerase chain reaction (PCR), and exon 5 of each gene was analyzed. The prevalence of congenital red-green CVD in this study was 3.46% in males and 0.14% in females. The PCR analysis of the first gene, downstream gene, and last gene revealed normal patterns in 73 normal cases. Seven unusual patterns were detected in two proton carriers and five deutan carriers. Among the randomly selected females, 8.8% (7/80) were CVD carriers. The prevalence of CVD among male Taiwanese students in this study was 3.46%. Female carriers of congenital CVD can be identified by molecular analysis of the visual pigment genes. The proportion of CVD carriers among the randomly selected females was 8.8%, which was slightly higher than expected and further studies are warranted.

The prevalence of red-green color vision deficiency and its related factors in an elderly population above 60 years of age.

To determine the prevalence of red-green (RG) color vision deficiency (CVD) in an elderly population and its related factors. This report is a part of the Tehran Geriatric Eye Study: a cross-sectional population-based study that was conducted on the elderly population (≥60y) of Tehran, Iran using multi-stage stratified random cluster sampling. All study participants underwent complete ocular examination, including the measurement of uncorrected and best-corrected visual acuity, objective and subjective refraction, and slit-lamp biomicroscopy. The color vision was tested using Ishihara plates with the near optical correction in place. Of the 3791 invitees, 3310 participated in the study. The data of 2164 individuals were analyzed after applying the exclusion criteria. The prevalence of R-G CVD was 3.73% (95%CI: 2.37%-5.09%) in the whole sample; the prevalence of protanomaly, protanopia, and deuteranopia was 1.51%, 1.76%, and 0.45%, respectively. The prevalence of R-G CVD was significantly higher in males than in females. The prevalence of RG CVD increased with advancing age from 2.91% in the age group 60-64y to 5.8% in the age group ≥80y (P=0.070). According to the multiple logistic regression model, male sex, and glaucoma were significantly related to RG CVD. Older age and hypertension also had a marginally significant relationship with RG CVD. Changes in color vision occur in the elderly due to the aging process and some physiological and pathological factors. Since the change in visual perception may affect the person's performance, this aspect of the visual system's function should also be taken into consideration in the examinations of the elderly.

Little information loss with red-green color deficient vision in natural environments

Inherited color vision deficiency affects red-green discrimination in about one in twelve men from European populations. Its effects have been studied mainly in primitive foraging but also in detecting blushing and breaking camouflage. Yet there is no obvious relationship between these specific tasks and vision in the real world. The aim here was to quantify the impact of color vision deficiency by estimating computationally the information available to observers about colored surfaces in natural scenes. With representative independent sets of 50 and 100 hyperspectral images, estimated information was found to be only a little less in red-green color vision deficiency than in normal trichromacy. Colorimetric analyses revealed the importance of large lightness variations within scenes, small redness-greenness variations, and uneven frequencies of different colored surfaces. While red-green color vision deficiency poses challenges in some tasks, it has much less effect on gaining information from natural environments.

Spatial Cognition Effects of IVE Teaching Resources on Red-Green Color Blindness

Immersive Virtual Environments can provide users with a sense of spatial presence and experience. But learners with Color Vision Deficiency cannot receive information entirely in the environments because they are difficult to distinguish some or all colors. This study selects learners with red-green color blindness as the sample, and designs three kinds of barrier-free Teaching Resources based on a color scheme and color contrast to explore their impacts on spatial cognition and learning experience. The experimental results show that the Color Adjusted Teaching Resources has significant differences both in learning satisfaction and technology acceptance, and the Contrast Adjusted Teaching Resources performs an important role in improving spatial cognition and technology acceptance. In addition, the Color and Contrast Adjusted Teaching Resources is significantly different from the Color Adjusted Teaching Resources in spatial cognition. Therefore, the findings indicated that the barrier-free color scheme and higher contrast of Teaching Resources can significantly improve spatial cognition, learning satisfaction, and technology acceptance of learners with red-green color blindness. To some extent, the research results can contribute to the design of barrier-free Teaching Resources about red-green color blindness.

BRIDGING DESIGNER-USER GAP WITH A VIRTUAL REALITY-BASED EMPATHIC DESIGN APPROACH: CONTEXTUAL INFORMATION DETAILS

AbstractWithout shared experiences, empathy gaps between designers and users are difficult to bridge. Advancing Virtual Reality (VR) has shed new light on this regard by enabling designers to simulate and experience their users' living scenarios in a virtual environment (VE). However, implementing VR-based empathetic design approach requires dealing with critical design questions, such as: (1) whether VR operators can develop empathy for unfamiliar user groups solely based on objective experience and (2) whether VR operators can utilize task-irrelevant contextual information in the VEs. To explore these issues, we designed an experiment based on two VEs with varying levels of detail that simulated the scenes viewed by people with red-green color vision deficiency (CVD). Participants were randomly assigned to either detail-rich or detail-simple VEs to complete neutral item-searching tasks. Results indicate that objective and neutral experience alone cannot elicit empathy towards users, and VR operating designers will utilize task-irrelevant contextual information.

Unique Haplotypes in OPN1LW as a Common Cause of High Myopia With or Without Protanopia: A Potential Window Into Myopic Mechanism.

Specific haplotypes (LVAVA, LIVVA, and LIAVA) formed by five polymorphisms (p.L153M, p.V171I, p.A174V, p.I178V, and p.S180A in exon 3 of OPN1LW) that cause partial or complete exon skipping have been reported as unique genetic causes of high myopia with or without colorblindness. This study aimed to identify the contribution of OPN1LW to early-onset high myopia (eoHM) and the molecular basis underlying eoHM with or without colorblindness. Comparative analysis of exome sequencing data was conducted for 1226 families with eoHM and 9304 families with other eye conditions. OPN1LW variants detected by targeted or whole exome sequencing were confirmed by long-range amplification and Sanger sequencing, together with segregation analysis. The clinical data were thoroughly analyzed. Unique haplotypes and truncation variants in OPN1LW were detected exclusively in 68 of 1226 families with eoHM but in none of the 9304 families with other visual diseases (P = 1.63 × 10-63). Four classes of variants were identified: haplotypes causing partial splicing defects in OPN1LW (LVAVA or LIVVA in 31 families), LVAVA in OPN1LW-OPN1MW hybrid gene (in 3 families), LIAVA in OPN1LW (in 29 families), and truncations in OPN1LW (in 5 families). The first class causes partial loss of red photopigments, whereas the latter three result in complete loss of red photopigments. This is different from the replacement of red with green owing to unequal re-arrangement causing red-green colorblindness alone. Of the 68 families, 42 affected male patients (31 families) with the first class of variants (LVAVA or LIVVA in OPN1LW) had eoHM alone, whereas 37 male patients with the latter 3 classes had eoHM with protanopia. Adaptive optics retinal imaging demonstrated reduced cone regularity and density in men with eoHM caused by OPN1LW variants compared to those patients with eoHM and without OPN1LW variants. Based on the 68 families with unique variants in OPN1LW, our study provides firm evidence that the two different phenotypes (eoHM with or without colorblindness) are caused by two different classes of variants (partial splicing-effect haplotypes or complete splicing-effect haplotypes/truncation variants, respectively). The contribution of OPN1LW to eoHM (isolated and syndromic) was characterized by OPN1LW variants found in 5.5% (68/1226) of the eoHM families, making it the second most common cause of monogenic eoHM alone (2.4%) and a frequent cause of syndromic monogenic eoHM with colorblindness. Such haplotypes, in which each individual variant alone is considered a benign polymorphism, are potential candidates for other hereditary diseases with causes of missing genetic defects.

Typical and Atypical Errors made by Color Normal and Defective Observers on Printed Pseudoisochromatic Color Vision Tests

Background: Pseudoisochromatic color vision tests are commonly used to screen for color vision deficiency (CVD). Although most color vision normal (CVN) individuals read all plates correctly, a remarkable proportion have errors. Objective: This study aimed to determine the typical and atypical error responses to the Ishihara and Waggoner PIP24 (W-PIP24) tests of CVN and CVD individuals. Methods: This study recruited 59 CVN and 63 congenital red-green CVD individuals. Participants were tested with the Ishihara and W-PIP24 tests. The participants’ responses were recorded, and typical and atypical errors were determined. Results: The rate of atypical errors in the CVN group was 21% in the Ishihara test and 9% in the W-PIP24 test, while those in the CVD group were 100% and 60%, respectively. The CVN and CVD groups tended to have more atypical errors on the Ishihara test than on the W-PIP24 test. Moreover, CVD individuals tended to have more atypical errors in the transformation plates in both tests. Conclusion: CVN individuals may misread the plates in the Ishihara and W-PIP24 tests for reasons other than the normality of color vision; therefore, counting only typical errors may eliminate the chance of CVN individuals misreading the number on the plates. The most significant finding of this study was that clinicians should perhaps only consider typical errors as “errors” on both tests.

Case report: Prolonged amelioration of mild red-green color vision deficiency following psilocybin mushroom use

Background Recent survey data indicate that some people report long-term improvement in color vision deficiency (CVD), also known as color blindness, following use of psychedelics such as lysergic acid diethylamide (LSD) and psilocybin. However, there are no objective data reported in the medical literature quantifying the degree or duration of CVD improvement associated with psychedelic use. Case presentation Here we present the case of a subject with red-green CVD (mild deuteranomalia) who self-administered the Ishihara Test to quantify the degree and duration of CVD improvement following the use of 5 g of dried psilocybin mushrooms. Self-reported Ishihara Test data from the subject revealed partial improvement in CVD peaking at 8 days and persisting for at least 16 days post-psilocybin administration. This improvement may have lasted longer, though the subsequent observations are confounded by additional substance use. Conclusion A single use of psilocybin may produce partial improvements in CVD extending beyond the period of acute effect, despite this condition typically resulting from a genetic defect. Systematic exploration of this possible phenomenon is needed to confirm our findings, gauge their generalizability, and determine the mechanism of action.

The prevalence of colour blindness among the males of the Bhoksha tribe in Dehradun, India

Colour Blindness is an X-linked recessive disorder which predominantly appears in males. Colour blindness is the inability or decreased ability to perceive colour differences by the human eye under normal lighting conditions. The purpose of the present study was to find out the prevalence of congenital Red-Green colour blindness among the people of the Bhoksha tribe in Dehradun district, Uttarakhand. The study was conducted with a total number of 204 individuals aged from 5 years to 85 years (mean ± SD is 22.71 ± 13.15) among the randomly selected male population. Colour blindness was examined using a standard Ishihara Chart under proper light. Among the total sample of 204 males in the community, 3 males are found to be colour blind which means that 98.53% were found to be normal, and the frequency of colour blindness was 1.47%. These three cases represented protanopia, deuteranopia and achromatopsia. Colour blindness appeared among the Pundir, Chauhan and Kakkad clans of the Bhoksha tribe in three villages. In conclusion, 1.47% were found to be colourblind in this study among the Bhoksha tribe of Dehradun, which is very high as compared with the prevalence in other tribal populations in India, although they were unaware of it. The present study supports Post and Pickford’s (1962, 1963) hypothesis of relaxation of selection.

Aids for color vision deficiency: introduction to the feature issue.

Approximately 8% of Caucasian males and 0.5% of females have congenital red-green color vision deficiencies (CVD), and a number of eye diseases are accompanied by acquired CVD. This feature issue includes ten contributions regarding existing and proposed algorithms and devices intended to help CVD subjects compensate for their color deficiencies. It also addresses limitations in the effectiveness of CVD aids for subjects with different types and degrees of color vision deficiency.

Effects of color-enhancing glasses on color vision in congenital red-green color deficiencies.

As commercially available glasses for color vision deficiency (CVD) are classified as low risk, they are not subject to stringent marketing regulations. We investigate how EnChroma and VINO glasses affect performance on the Colour Assessment and Diagnosis (CAD) test in individuals with CVD. Data were obtained from 51 individuals with red-green CVD. Blood or saliva samples were collected to examine the structure of the OPN1LW/OPN1MW array. Individuals completed the CAD test twice without glasses and once with each pair of glasses. Although there was a statistically significant effect of both glasses, only that of VINO could be considered functionally meaningful.