Ishihara Test Research Articles (Page 1)

Background: Individuals with colour vision impairments have a significant probability of misjudging colour. This high risk of colour-related inaccuracies is crucial for evaluating the ability of an individual to distinguish between different hues. The Waggoner computerised colour vision test (W-CCVT) is a novel colour test designed to detect colour vision deficiencies. Aim: This study aimed to validate the performance of the W-CCVT relative to that of the anomaloscope and Ishihara tests. Setting: This study evaluated the W-CCVT relative to standard colour vision tests by recruiting 52 participants with colour-normal vision and 135 with colour vision deficiencies from different locations in the capital city of Saudi Arabia. Methods: The performance of the W-CCVT was compared with that of the Ishihara test and the Heidelberg Multi-Colour Oculus anomaloscope. Participants were directed to identify the numbers on the Ishihara plates, and their responses were documented on a recording sheet. Results: Concerning pass or fail agreement, good agreement was observed between the W-CCVT and anomaloscope, with a first-order agreement coefficient of 0.97. The sensitivity value was 97.7% and 98% value for the specificity. Conclusion: The Waggoner computerised colour vision test may serve as a reliable alternative screening tool for detecting colour vision deficiencies. Contribution: The W-CCVT could be an appropriate screener colour vision test and a suitable alternative to the Ishihara test when implemented on an iPad.

Color vision deficiency (CVD), particularly red‐green color blindness, significantly impairs color discrimination in daily life. Conventional colored lenses and filters often suffer from dye leakage and poor biocompatibility, limiting their clinical use. In this article, colorblind‐correcting contact lenses are developed by chemically grafting a Rhodamine B derivative onto 2‐hydroxyethyl methacrylate‐based polymer networks. This covalent immobilization prevents dye leaching and confers selective light absorption within the 540–570 nm spectral range, thereby specifically targeting red‐green CVD. Compared with physical doping, the chemically grafted lenses exhibit over 95% dye retention, maintained mechanical and optical integrity, and demonstrated excellent biocompatibility with >95% cell viability in L929 and human corneal epithelial cells assays. Simulated clinical tests using the Ishihara plates revealed up to an 85% improvement in recognition accuracy. This approach presents a safe, stable, and effective pathway toward wearable visual correction technologies.

Color Vision Deficiency (CVD) affects over 300 million individuals worldwide, with protanopia and deuteranopia being the most common subtypes, causing red–green confusion. This study leverages machine learning to (a) classify reference (considered as normal vision) and simulated protanopia and deuteranopia Ishihara plate images, (b) generate corresponding enhanced versions of these images, and (c) provide improved textbook diagrams (from NCERT books) and other pseudochromatic figures for CVD students, validated through feedback from diagnosed individuals. Tritanopia and milder forms of CVD were excluded in this study. A dataset of 1,400 Ishihara plates was processed to simulate protanopia and deuteranopia perception via standard Red Green Blue (sRGB) to long-, medium-, and short-wavelength cone (LMS) modeling. Enhanced images were generated using a daltonization function defined by the error between reference and simulated images, with enhancement strength (α) optimized to maximize contrast gain while minimizing distortion. Feature embeddings from ResNet-50, EfficientNet-B0, and DenseNet-201 were fused and reduced via PCA, followed by One-vs-All (OvA) (classifiers: linear support vector machine, logistic regression, and decision tree), random forest, gradient boosting, and neural network. Results showed optimal enhancement at α = 0.54 for deuteranopia and 0.64 for protanopia, achieving contrast gains of 69.6 and 64.3, respectively, with minimal color distortion (ΔE ≈ 4.9) and negligible clipping (<0.002). The OvA strategy achieved 99.7% accuracy, while MLP reached 100% across metrics. Surveys with 15 diagnosed students confirmed substantial perceptual improvement: recognition of previously unreadable digits and symbols increased from <20% to full visibility, with mean ratings above 4/5 for enhanced images. The OvA technique integrated with daltonization can assist in enhancing Ishihara and educational images in real time.

Throughout the lifespan, humans exhibit varying abilities in perceiving color and luminance with sensitivity peaking at different stages. The interaction between luminance and color perception is likely influenced by the distinct developmental trajectories of the respective visual psychophysical channels. This study aimed to investigate how chromatic noise affects luminance discrimination thresholds in adolescents, young adults, and elderly individuals. Sixty participants with no visual complaints (20/20 or corrected binocular visual acuity, and no indication of color vision impairment in the Ishihara pseudoisochromatic plate test) were divided into three age groups: adolescents (15.7 ± 0.8 years), young adults (20–40 years), and elderly adults (60 + years). Participants underwent a luminance contrast discrimination task with chromatic noise masking using a mosaic stimulus, where four chromatic noise protocols were applied (protan, deutan, tritan, and a no-noise protocol). The results showed that luminance contrast thresholds were significantly elevated with the addition of chromatic noise in all groups compared to those without chromatic masking noise, but adults exhibited smaller differences in thresholds between the conditions with and without noise compared to participants in the adolescent and elderly groups (p < 0.05). The intergroup comparisons revealed that young adults had the lowest thresholds, followed by adolescents and elderly individuals (p ≤ 0.01). Elderly participants exhibited higher luminance thresholds than young adults in all chromatic noise conditions, especially under the tritan protocol. These findings suggest that the maturation of luminance and color interaction is consolidated after adolescence, with sensitivity peaking of the mechanisms of color-luminance interaction in adulthood and declining in the elderly. The study provides insights into the developmental and aging processes of color-luminance interaction mechanisms, highlighting the continued maturation of color processing mechanisms in adolescence and their subsequent decline with age.

Purpose – to study the prevalence of congenital color vision deficiency (CVD) in the young male population in Azerbaijan. Material and methods The study was conducted among young men who underwent examination at the National Ophthalmology Centre named after Academician Zarifa Aliyeva during the first 6 months of 2025. In the analytical, cross-sectional, population-based study, the results of general ophthalmological examination of 2988 men, including color vision test, were analysed. The pseudoisochromatic Ishihara test and Rabkin's polychromatic test were used to detect CVD. Young men with dichromacy and monochromacy were additionally involved in electroretinogram (ERG) examination. The statistical difference between the results was calculated, and the results were considered statistically significant for p&lt;0.05. Results The average age of the men included in the study was 21.4 ± 3.3. According to the results, congenital CVD was detected in 21 men (0.7%) among the examined young people. According to the prevalence of different types of CVD, deutranopia (35%) and deutranomaly (45%) were the most common forms of dyschromatopsia (p&lt;0.05). Protanomaly was observed in 10%, protanopia in 5%, and monochromacy in 5% of cases of CVD. Conclusion The results show that the prevalence of CVD in young male populations is lower than in other populations. Early detection of CVD plays an important role in eliminating psychosocial barriers in these individuals, including career choice and obtaining a driver's license. In this regard, color vision screening in populations covering different age groups is essential. Key words: color vision deficiency, congenital, dyschromatopsia, monochromacy

Assessing the accuracy of a digital color vision test.

Abstract PURPOSE: The purpose of the study was to assess color vision (CV) and contrast sensitivity (CS) in patients with primary angle closure glaucoma (PACG) and primary angle closure (PAC) and to correlate these changes with age-matched controls. In addition, to asses this correlation with optical coherence tomography (OCT) retinal nerve fiber layer (RNFL). MATERIALS AND METHODS: CV (using D-15 and Ishihara test) and CS (using Spaeth Richman Contrast Sensitivity Test [SPARCS] and Pelli Robson test) were analyzed in patients with PACG (Group 1) (33 eyes), PAC (Group 2) (27 eyes), and controls (Group 3) (60 eyes). OCT RNFL and Humphrey visual field testing was also done for cases and controls. RESULTS: Out of a total of 33 eyes in Group 1, 2 (6%) eyes had no defect, 20 (60.6%) had protan defects, 2 (6%) had deutran defects, and 9 (27.3%) eyes had tritan defects. Of the 27 eyes in Group 2, 1 (3.7%) eye had no CV defect, 19 (70.3%) eyes had protan defects, and 7 (25.9%) eyes had tritan defects. None of the eyes in Group 2 had a deutran defect. Forty-seven (78.3%) eyes from Group 3 had no CV defect, 10 eyes (16.6%) had a protan defect, and 3 (5%) of the eyes showed a tritan defect. All Group 1 and Group 2 eyes had a C-Index of &gt;1.4. Twenty-eight eyes had a total SPARCS score &lt;70, 18 eyes belonged to Group 1, and 10 eyes belonged to Group 2. There was no statistically significant difference in central and peripheral CS (in all the quadrants) between Groups 1 and 2. CONCLUSION: Qualitative and functional vision parameters are affected even in PAC patients before PACG sets in clinically. Hence, early and regular screening of these parameters is required.

To evaluate structural and visual functional parameters in ethambutol-related toxic optic neuropathy (EON). In this prospective study, we recruited 95 adults with EON presenting within 1 month of onset and 100 age-matched healthy controls. Best-corrected visual acuity (Early Treatment Diabetic Retinopathy Study chart), colour vision (Ishihara pseudoisochromatic plates), contrast sensitivity (Pelli-Robson chart), Humphrey visual field analysis (HVF 30-2 Swedish Interactive Threshold Algorithm-FAST), visual evoked response and spectral domain optical coherence tomography for macular ganglion cell-inner plexiform layer (mGC-IPL), retinal nerve fibre layer (RNFL) and papillomacular bundle (PMB) analyses were done at baseline, 3 months and 6 months. Almost 52% eyes showed significant visual improvement of ≥ 2 Snellen lines after stopping the drug. RNFL (cases-100.84±21.87 µm vs controls-98.05±7.21 µm; p=0.37) and PMB thickness (cases-51.10±17.26 µm vs controls-53.45±6.42 µm; p=0.19) in cases were comparable with controls at baseline, but showed significant thinning at 6 months follow-up (RNFL -83.77±21.06 µm; PMB-30.96±11.02 µm; p<0.0001 for both). Average GC-IPL thickness (cases-29.66±6.86 µm; controls-39.68±2.59 µm) and ganglion cell-inner plexiform layer (GCL) volume (cases-0.85±0.17 mm3; controls-1.08±0.069 mm3) was significantly less as compared with controls (p<0.0001 for all) at baseline and showed significant further deterioration on follow-up (p<0.001 for all). The average GC-IPL thickness (p value :<0.0001, r:-0.31), GCL volume (p value :<0.000, r:-0.29) and PMB thickness (p value :0.043, r:-0.14) showed a significant negative correlation with final vision at 6 months. Progressive structural damage despite visual improvement raises concern about the irreversible nature of EON. PMB, GC-IPL thickness and GCL volume are better predictors of visual recovery in EON.

Objectives: To observe the prevalence of color vision disorder (CVD) in district Karak, Khyber Pakhtunkhwa (KP) Pakistan from September 2023 to September 2024. Methodology: During this field work, samples of 555 (300 male and 255 female) individuals were collected from surrounding locations, i.e. Karak city, Metha khel, Landiwa, Thth-e-Nasrati, Gurguri, Latamber, Banda Dawood Shah and Shagi Banda. The data were collected via a predesigned questionnaire printed in Urdu and English, and the history of consanguinity of parents was also recorded. Results: We used Ishihara test, City University test (CUT) and Farnsworth D-15 to identify color blind people, revealed that 28 people (5.04%) were color blind. Out of these, 19(67.85%) were males and 9(32.14%) were females. Among these, 28 color blind individuals, 16(57.14%) were red-green color blind, 5 (17.855) were red color blind, 5 (17.85%) were green color blind and 2 (7.14%) were blue color blind. Furthermore, consanguinity of parents was recorded and interestingly all affected individual parents had consanguineous marriages. Two different types of pedigree analysis were recorded too. In the collected data, people aged between 18 to 60 years were present. Conclusion: We found a significant prevalence of CVD in males (6.3%) than in females (3.5%). The study is significant in that it reported the prevalence of color blindness for the first time in Southern KP, Pakistan. This study provides the foundational understanding of CVD and its prevalence in district Karak and a framework for further research and prevention strategies regarding CVD.

Background/Objectives: As high-acuity vision is limited to a very small visual angle, examination of a scene requires multiple fixations. Simultanagnosia, a disorder wherein elements of a scene can be perceived correctly but cannot be integrated into a coherent whole, has been parsed into dorsal and ventral forms. In ventral simultanagnosia, limited visual integration is possible. This case study was the first to record gaze during the presentation of a series of visual stimuli, which required the processing of local and global elements. We hypothesised that gaze patterns would differ with successful processing and that feature integration could be disrupted by distractors. Methods: The patient received a neuropsychological assessment and underwent CT and MRI. Eye movements were recorded during the following tasks: (1) famous face identification, (2) facial emotion recognition, (3) identification of Ishihara colour plates, and (4) identification of both local and global letters in Navon composite letters, presented either alone or surrounded by filled black circles, which we hypothesised would impair global processing by disrupting fixation. Results: The patients identified no famous faces but scanned them qualitatively normally. The only emotion to be consistently recognised was happiness, whose scanpath differed from the other emotions. She identified none of the Ishihara plates, although her colour vision was normal on the FM-15, even mapping an unseen digit with fixations and tracing it with her finger. For plain Navon figures, she correctly identified 20/20 local and global letters; for the “dotted” figures, she was correct 19/20 times for local letters and 0/20 for global letters (chi-squared NS for local, p < 0.0001, global), with similar fixation of salient elements for both. Conclusions: Contrary to our hypothesis, gaze behaviour was largely independent of the ability to process global stimuli, showing for the first time that normal acquisition of visual information did not ensure its integration into a percept. The core defect lay in processing, not acquisition. In the novel Navon task, adding distractors abolished feature integration without affecting the fixation of the salient elements, confirming for the first time that distractors could disrupt the processing, not the acquisition, of visual information in this disorder.

ABSTRACT The eye, as one of the five sensory organs where optic and neural structures are integrated, carries information from the environment to the brain. This information processed in the brain provides image formation. However, visual problems may occur due to environmental, physical, or genetic reasons. Color blindness is one of these problems. It negatively affects the way individuals perceive colors. But, it is possible to improve the visual experience on digital images for color blind patients. Especially, image processing offers enriched content. In this study, a three‐stage original image processing filter was improved to enhance the perception level of color blind individuals regarding digital images. These filters were applied to Ishihara test plates, which are actively used in the diagnosis of color blindness. Then, enhanced images was simulated for color blind patients. This process was also done for the original images. In the last stage, in order to provide an objective evaluation, the simulated images related to the original images and enhanced images were classified with the MobileNetv2 transfer learning method. The classification results prove that the proposed filters improve visual perception in each of the seven different color blindness types in patients.

Creating grayscale images from a color reality has been an inherent human practice since ancient times, but it became a technological challenge with the advent of the first black-and-white televisions and digital image processing. Decolorization is a process that projects visual information from a three-dimensional feature space to a one-dimensional space, thus reducing the dimensionality of the image while minimizing the loss of information. To achieve this, various strategies have been developed, including the application of color channel weights and the analysis of local and global image contrast, but there is no universal solution. In this paper, we propose a bio-inspired approach that combines findings from neuroscience on the architecture of the visual system and color coding with evidence from studies in the psychology of art. The goal is to simplify the decolorization process and facilitate its control through color-related concepts that are easily understandable to humans. This new method organizes colors in a scale that links activity on the retina with a system of opponent and complementary channels, thus allowing the adjustment of the perception of warmth and coolness in the image. The results show an improvement in chromatic contrast, especially in the warmth and coolness categories, as well as an enhanced ability to preserve subtle contrasts, outperforming other approaches in the Ishihara test used in color blindness detection. In addition, the method offers a computational advantage by reducing the process through direct pixel-level operation.

ABSTRACTVarious simulation methods of color appearance for dichromats or anomalous trichromats have been proposed over the years. To further improve the performance of the simulation model and extend the application range to both dichromats and anomalous trichromats, we have proposed a simulation model of cone fundamentals specifically designed for individuals with red–green type color vision deficiency (CVD) based on the CIE 2006 physiological observer model. By utilizing the simulated cone fundamentals, it becomes possible to predict the color appearance of real scenes and digital images for CVD. The fundamental premise of the new model is rooted in the hypothesis that CVD arises from a shift in the peak wavelength of the photopigment absorption spectrum of the L‐ or M‐cone. Instead of simply maintaining the waveform without alteration as observed in prior studies, we altered waveforms of the absorption spectra of anomalous L‐/M‐cone photopigments when adjusting their peak wavelengths. Regarding different shapes in the absorption spectrum between the L‐ and M‐cones, the absorption spectrum of the anomalous L‐/M‐cone was obtained by combining the peak wavenumber shift and linear interpolation of spectral quantal absorption curves between L‐ and M‐photopigments in the wavenumber domain. The performance of the proposed model was substantiated through experimental validation by the pseudoisochromatic plates and Farnsworth Munsell 100 Hue test (FM‐100). The findings revealed a high level of consistency between the model prediction and the actual perception reported by individuals with CVD.

BackgroundColor vision and memory are potential markers of Alzheimer’s disease (AD); however, information regarding their changes in early AD remains limited.ObjectiveThe aim of this study was to evaluate color recognition memory in mild cognitive impairment (MCI), early Alzheimer’s disease (AD), and older adults with normal cognition, as well as to assess its diagnostic properties.MethodsWe included 27 participants with mild dementia (MD), 25 with MCI, and 25 older adults with normal cognition who served as the control group (CG). Participants completed the Mini-Mental Status Examination (MMSE), the Clinical Dementia Rating (CDR), and the Alzheimer’s disease Assessment Scale-Cognitive Subscale (ADAS-Cog 13) for cognitive assessment; delayed word recall (after 30 min), the Ishihara test, and a color recognition memory test were also administered. The color recognition memory test was performed using a basic 12-color kit displayed on a computer screen. Color recognition was evaluated after 5 and 30 min using four initial stimuli and four new colors from the 12-color kit. Participants were required to recognize which of the eight randomly presented colors they had previously seen.ResultsSignificant differences were observed in the total error scores for color recognition memory among the three groups. Medians (interquartile range) for CG, MCI, and MD groups were 2 (2), 4 (2), and 5 (3) respectively. A Kruskal–Wallis test returned a significant p-value (p < 0.001); post-hoc analysis of group pairs was then conducted for CG and MCI (p < 0.001), MCI and MD (p = 0.007), and CG and MD (p < 0.001). Using demographic information and ADAS-Cog 13 scores as predictors, a multinomial logistic regression model accurately categorized 77.9% of cases (96% of CG, 64% of MCI, and 74.1% of MD cases). Adding the color memory total error score to the model improved accuracy to 84.4% (100% of CG, 76% of MCI, and 77.8% of MD cases).ConclusionColor recognition memory test results differed significantly between participants with normal cognition and those with MCI and early AD. Therefore, it may help in the early diagnosis of AD as a simple, non-invasive diagnostic marker.

This network meta-analysis (NMA) was done to compare the performance of color vision tests in the detection of individuals with color vision deficiency (CVD). Medline (via PubMed), Embase, and Web of Science were comprehensively searched from inception of the databases to 17 January, 2023. Conventional meta-analysis of diagnostic indicators was performed. The superiority of a diagnostic approach was depicted using the Superiority (S) Index. Six studies were enrolled. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve of summary receiver operating characteristic of the Ishihara tests were 0.89 (0.81, 0.94), 0.99 (0.96, 1.00), 110.8 (18.1, 677.0), 0.10 (0.05, 0.20), 1105 (112, 10,930), and 0.98 (0.96, 0.99). Waggoner Computerized Color Vision Test ranked the best performance in the detection of CVD, followed by CAD test, Ishihara test, Fletcher Lantern test, and HHR test as the rest second to the fifth most effective modalities. This NMA revealed that CAD test, Ishihara test, Fletcher Lantern test, and HHR test had favorable diagnostic validity in the detection of CVD.

Background: Diabetic retinopathy is a progressive microvascular complication of diabetes mellitus and a leading cause of vision impairment among adults. As the disease progresses, visual functions such as visual acuity, contrast sensitivity, and color vision can deteriorate. Argon laser photocoagulation is a widely used treatment for proliferative diabetic retinopathy. However, its effect on functional vision parameters beyond visual acuity is still under-evaluated, particularly in the local population context. Objective: To evaluate changes in visual functions including visual acuity, contrast sensitivity, and color vision before and after Argon laser photocoagulation in patients with diabetic retinopathy. Methods: This comparative cross-sectional study was conducted at the Department of Ophthalmology, University of Lahore Teaching Hospital, from February to May 2024. A total of 55 patients (30 males, 54.5%; 25 females, 45.5%) aged 40–60 years with a diabetes duration of more than three years were enrolled using a non-probability convenience sampling method. Visual acuity, color vision, and contrast sensitivity were assessed using the Snellen chart, Ishihara plates, and Pelli-Robson chart respectively, before and four weeks after Argon laser treatment. Data were recorded in a structured performa and analyzed using SPSS version 27. Pearson correlation was used to assess relationships between visual parameters. Results: The mean contrast sensitivity decreased slightly from 1.5073 ± 0.23891 to 1.4745 ± 0.21406 (p=0.45), while visual acuity showed a minor reduction from 5.55 ± 1.245 to 5.49 ± 2.081 (p=0.87). A significant improvement was observed in color vision scores, which increased from 2.45 ± 1.168 to 3.35 ± 1.280 (p&lt;0.001). Conclusion: Post-treatment, color vision showed significant enhancement, while visual acuity and contrast sensitivity remained largely unchanged. These results suggest that Argon laser therapy may selectively improve certain visual functions in patients with diabetic retinopathy.

ABSTRACT Various methods, including the Farnsworth – Munsell 100 hue test, Ishihara test, Nagel anomaloscope, etc. have been proposed for diagnosing color vision deficiency. Despite their prevalence, these methods exhibit potential misjudgments in diagnosis. This inherent limitation stems from the oversight of individual differences in physiological parameters of the human visual system within the population. This paper introduces a color vision deficiency examination method based on the reconstruction of LMS cone fundamentals. The cone fundamentals are derived from the optimization of seven physiological parameters using matching results of multiple color pairs, categorized into three groups: Rayleigh match, Moreland match, and white match. All the pairs within each group vary in the peak wavelength of the narrow-band primary, except for the white channels, which have broader bandwidths. The accuracy of reconstructed cone fundamentals has been verified through k-fold cross-validation. The reconstructed cone fundamentals provide a basis for the accurate estimation of the type and severity of color vision abnormalities. Importantly, it has been demonstrated that the diagnosis results are consistent with those obtained by the Ishihara test, RCCT, BCVT, and CBC test confirming the reliability of the proposed methodology.

To compare the Ishihara test errors scores of colour vision deficiency (CVD) subjects when wearing four different types of red-tinted contact lenses (RCL) that differ in their transmittance as determined using a spectrophotometer. Six congenital CVD subjects volunteered to participate in this study. Ishihara plates were used to determine the colour vision errors made, whereas Farnsworth-Munsell 100 Hue test was conducted to determine the total error scores (TES) and type of CVD. Four types of RCL (Types A, B, C and D) were inserted in the non-dominant eye and tested in a randomised manner by a masked operator. Errors scores in Ishihara test were determined at baseline without any contact lens and after wearing the four different RCL. The subjects were then divided into two groups based on the mean TES. Repeated measures ANOVA with Greenhouse-Geisser corrections showed that there was a highly significant effect of RCL type on Ishihara error score [F(2.056, 10.282)=30.214, P<0.001]. Error scores with RCL Type B were significantly lower than errors made when no lens was worn, and with RCL Type C and Type D (all P<0.001). Error scores with RCL Type B were also lower than those made with RCL Type A, however, they were not significantly different. For subjects with TES values less than 180, RCL type B showed the largest improvement in Ishihara error score (50%) compared to the other three RCLs. RCL type A showed the best performance in TES value of more than 180, with an improvement of 80% in Ishihara score. RCL Type A has the lowest transmittance at the confusion wavelength (450-568 nm), followed by RCL Types B, D and C. This study shows that RCL can improve Ishihara error scores. RCL with lower transmission at 450-568 nm and 90% transmittance beyond 637 nm are the most effective. Lenses which could block more light between 550-580 nm are more effective for colour defectives with more severe colour defects.

Background: Workers in the textile industry are exposed to occupational hazards that can adversely affect visual functions. Prolonged exposure to bright light, mechanical strain, and hazardous chemicals may contribute to visual impairments, including refractive errors, glare sensitivity, and ocular injuries. Limited research has comprehensively assessed multiple visual functions among textile workers, particularly in Pakistan. This study aims to evaluate visual acuity, contrast sensitivity, glare sensitivity, color vision, and visual field integrity in textile industry workers, identifying potential occupational risks affecting their ocular health. Objective: To assess visual functions and determine the magnitude of work-related visual problems among textile industry workers in Lahore. Methods: A cross-sectional survey was conducted among 93 textile workers aged 15–45 years. Visual acuity was measured using the LogMAR chart, color vision using Ishihara plates, visual field by confrontation testing, contrast sensitivity using Lea number plates, and glare sensitivity by targeted light exposure. Participants provided informed consent before data collection, and a structured questionnaire recorded demographic details, ocular complaints, and work-related risk factors. Data were analyzed using SPSS 20.0, applying descriptive statistics and comparative analyses where appropriate. Results: Among 93 participants, 10% were male and 90% female. Normal visual acuity was recorded in 56 (61%) workers, while myopia was found in 43 (46.2%). Glare sensitivity was detected in 22 (24%), contrast sensitivity was deficient in 14 (15.2%), and color vision deficiency was observed in 4 (4.3%). Bright light exposure was reported by 88 (94.6%) workers. Five (5.4%) workers had vision-threatening ocular diseases, including cataract (3.2%) and diabetic retinopathy (2.2%). Protective devices were provided to all workers, contributing to a lower rate of ocular injuries. Conclusion: This study highlights that textile workers are at significant risk of refractive errors, with myopia being the most prevalent. While color vision and contrast sensitivity impairments were less frequent, glare sensitivity was notable. Cataract and diabetic retinopathy were detected in older workers. Protective eyewear contributed to a reduced incidence of ocular injuries, underscoring the importance of workplace safety measures and routine ophthalmic screening.

Objective This study aimed to identify the prevalence of Color Vision Deficiency (CVD) and its contributing factors among medical students enrolled at King Saud bin Abdulaziz University for Health Sciences in Riyadh, Saudi Arabia. Methods In this cross-sectional study, 522 students from King Saud bin Abdulaziz University for Health Sciences in Riyadh, Saudi Arabia, participated. The student filled out the questionnaire immediately after completing the Ishihara test. Data analyses were conducted in SPSS. Results Of 522 students, 29.9% were females, and 70.1% were males. The prevalence of CVD in medical students was 1.5%, with 98.3% of students having normal vision while 0.2% had small changes or misdiagnosed CVD. All eight students with a definitive diagnosis of CVD were males, with a significant association (p=0.04) between sex and CVD status. There was a significant association of CVD status with the familial history of CVD (p=0.002) and history of congenital color vision abnormality (p=0.0342). No significant associations were found for the knowledge of CVD, history of vision problems, eye surgery, eye or head trauma, any exposure to chemicals, current health status, and vitamin A intake. Conclusion The CVD prevalence reported by our study is the lowest compared to all other studies in medical students worldwide. A considerable number of medical students were unaware of their vision problems. Therefore, preliminary screening of all school-going students is recommended to ensure they are aware of their medical condition and minimize the potential difficulties faced during studies and clinical work.