Prevalence of Color Vision Deficiency among Medical Students

Introduction Color vision deficiency (CVD) constitutes one of the frequently observed eye disorders in all human populations. Color is a prominent sign utilized in the medical profession to study and identify histopathological specimens, lab instruments, and patient examination. Color deficiency affects the medical skills of students resulting in poor clinical examination and color appreciation. There is no effective screening of CVD at any level of the medical profession. Hence, this study was aimed to determine the prevalence of CVD among medical students. Materials and methods This was a cross-sectional study conducted from September 2019 to February 2020 over a period of six months in Karachi, Pakistan. All medical students aged 18-21 years of either gender enrolled in the first and second years of medical college were included in this study. The examination was performed during daylight. Ishihara plates were placed at a distance of 75 cm from the subject and tilted so that the plane of the paper lies perpendicular to the line of vision. Students were given five seconds to read the plate and one examiner was instructed to mark the checklist. A score of less than 12 out of 14 red/green test plates (not including the demonstration plate) was considered as a CVD. All statistical analysis was performed using Statistical Package for Social Sciences version 20.0 (Armonk, NY: IBM Corp). Results The mean age of the medical students was 19.61± 1.22 years. There were (n=123) 53.0% females and (n=111) 47.0% males. Most of the medical students (n=131, 56.0%) belonged to the upper-middle-class socioeconomic group. CVD was observed in (n=13) 6.0%of medical students. Age (p=0.001) and socioeconomic status (p=0.001) were the only demographic factors significantly associated with color deficiency. Conclusions Color deficiency, although an unnoticed concern, is fairly common among medical students. Medical students must be screened for CVD as this will enable them to be aware of their limitations in their future observational skills as a doctor and devise ways of overcoming them in clinical practice.

Examining Spatial Attributes for Color Deficient Observers

Color deficiency is a common affliction for males, with about 8% of the male population suffering from some form of – colloquial – color blindness. In common description, this is interpreted as the inability to perceive certain colors from a sensory standpoint. If that description is sufficiently complete, spatial attributes of the color signal should not influence the visual experience of a Color Deficient Observer (CDO).In this paper we describe the set-up and results of an experiment that is intended to vary the spatial attributes of a color deficiency test when shown to an observer. For this, we modified color vision charts to maintain their colorimetric attributes while varying spatial attributes and we measured color deficient observers with respect to their response accuracy and their response speed. We show results that indicate that there is a clear influence of color proximity in the responses.

Color image evaluation of congenital red-green color deficient and normal color vision observers

How and to what extent the increase of Cab * affects on various subjective evaluations for congenital red-green color deficiency (CVD) and normal color vision (NCV) observers was investigated using scenery, food, and graph images. Results of "Pale vs Deep" evaluation indicate similar tendency for all color vision types in all test images, indicating that CVDs recognize the saturation change of images similar to NCVs using some kind of strategy. Individual differences of the CVDs in the results of other adjective pairs such as "Unnatural vs Natural" are generally larger than those of NCVs. Some color combinations in the graph images are indiscriminable for either protan or deutan, and thus are not recommended to be used.

Frequency of Color Vision Deficiency among Saudi Dental Students: A Cross-Sectional Study

Objective The current research was conducted to evaluate the frequency of color-vision deficiency among dental students of King Khalid University College of Dentistry, Saudi Arabia. Materials and Methods A cross-sectional study was performed among 203 dental students working as interns at male and female dental clinics of King Khalid University College of Dentistry (KKUCOD), Saudi Arabia. The Ishihara color-vision deficiency (CVD) test with 24 plates was used for diagnosis of the problem. Analysis of the data was done by performing Chi-square tests using SPSS software version 20. Results The frequency of total CVD was found to be 3.9%. While the association of gender with total CVD was observed to be statistically nonsignificant, a statistically significant relation was drawn with red-green color deficiency. Out of the total of 203 patients, 44 males were identified with red-green color deficiency, whereas only three females were found to have this condition, therefore revealing that CVD is more prevalent in males. Age was found to have a significant association with red-green color vision deficiency, protanopia, and total CVD. Conclusion A total of 20.19% male dental students had red-green color vision deficiency compared to 1.4% in female students. The dental students must be aware of their congenital color vision deficiency and its impact on their professional life. Screening of such dental students and professionals is quite important so that they can tackle the color vision problems well without having detrimental effect on their future dental practice.

Application of spectral computing technics for color vision testing using virtual reality devices

Color deficiency tests are well known all over the world. However, there are not applications that attempt to simulate these tests with total color accuracy in virtual reality using spectral color computing. In this work a study has been made of the tools that exist in the market in VR environments to simulate the experience of users suffering from color vision deficiencies (CVD) and the VR tools that detect CVD. A description of these tools is provided and a new proposal is presented, developed using Unity Game Engine software and HTC Vive VR glasses as Head Mounted Display (HMD). The objective of this work is to assess the ability of normal and defective observers to discriminate color by means of a color arrangement test in a virtual reality environment. The virtual environment that has been generated allows observers to perform a virtual version of the Farnsworth-Munsell 100 Hue (FM 100) color arrangement test. In order to test the effectiveness of the virtual reality test, experiments have been carried out with real users, the results of which we will see in this paper.

Improving Discrimination in Color Vision Deficiency by Image Re-Coloring

People with color vision deficiency (CVD) cannot observe the colorful world due to the damage of color reception nerves. In this work, we present an image enhancement approach to assist colorblind people to identify the colors they are not able to distinguish naturally. An image re-coloring algorithm based on eigenvector processing is proposed for robust color separation under color deficiency transformation. It is shown that the eigenvector of color vision deficiency is distorted by an angle in the λ , Y-B, R-G color space. The experimental results show that our approach is useful for the recognition and separation of the CVD confusing colors in natural scene images. Compared to the existing techniques, our results of natural images with CVD simulation work very well in terms of RMS, HDR-VDP-2 and an IRB-approved human test. Both the objective comparison with previous works and the subjective evaluation on human tests validate the effectiveness of the proposed method.

Stereoacuity of Black-White and Red-Green Patterns in Individuals with and without Color Deficiency

Background. Chromatic contrast may affect stereopsis. Daltonism is a common color deficiency in which the colors red and green are incorrectly detected. The aim of this study was to evaluate the stereoacuity of color-defective individuals presented with color symbols that they see defectively. Methods. Ten students diagnosed with daltonism and 10 students with normal color vision were recruited. A stereopsis test system using a phoropter and two 4K smartphones was used. Contour-based graphs and random-dot graphs with black versus white and red versus green patterns were used as test symbols. The Wilcoxon signed rank test was used to test the difference between groups. Results. No significant difference in stereoacuity was found between contour-based and random-dot graphs within both daltonism cohort and normal color vision cohort (P>0.05). A significant difference in stereoacuity was found between the black-white (P=0.005) and red-green (P=0.007) graphs for the daltonism cohort, while no significant difference in stereoacuity was found for the normal color vision cohort (P>0.05). Conclusion. Chromatic contrast is an influential factor for stereopsis measurement in individuals with color deficiency.