Color Blindness In Dental Students And Staff- An Obstacle In Shade Selection For Restorations .

Dentists having defective color vision may be unaware of their defect or may have problems in perceiving color as normal vision dentists do. People who are "color vision defective" tend to be missing some of the color-sensitive cones, so these colors will appear darker. The aim of the present study is to 1. estimate the number of dental students/ personnel having problems in color discrimination based on a color blindness test 2. To refer the students/ personnel to a specialist for confirmative diagnosis. 3. To provide alternate options for shade selection to the same. Dental students, dental teachers and dental technicians/ dental auxiliaries were randomly selected for the study, with a sample size of 400 with age range of 17 to 35 out of which 200 were males and 200 females. An Ishihara color blindness test (numbers made up of color dots) was conducted to screen the dental personnel for color defective vision in the same room and in the same light source. 5% of the male and 0% of female dental personnel/ students were found to be color vision defective. Counseling to such students and personnel required to take assistance in appointments of shade selection / matching.

Color Vision Defect in Diabetic Retinopathy by Computerized Color Test

PURPOSE: To investigate the color vision defect in diabetic patients using the SNU computerized color test (SCCT). METHODS: From May to September 2003, diabetic patients with visual acuity 0.6 or better underwent various examinations including biomicroscopy, fundus photography, Ishihara color test, Hardy?Rand?Rittler (HRR) test, Seohan computerized hue test (SCHT), and SNU computerized color test. The SCCT was developed by using the Matlab 6.0 program. RESULTS: A total of 160 eyes of 82 diabetic patients were included. Thirty-two patients had no diabetic retinopathy, 19 had mild nonproliferative diabetic retinopathy (NPDR), 12 had moderate NPDR, 12 had severe NPDR, and 7 had proliferative diabetic retinopathy (PDR). In the all diabetic patients, the average total error score (TES) of SCHT was 189 and that of SCCT was 8.5; in patients without diabetic retinopathy, the scores were 125 and 3.64; in patients with mild NPDR, 185 and 8.16; in patients with moderate NPDR, 209 and 11.1; in patients with severe NPDR, 288 and 15.6 ; and in patients with PDR, 324 and 17.6 respectively. On the HRR test, patients without diabetic retinopathy had 1 tritan defect; those with mild NPDR 2 tritan, 2 protan, and 2 deutan defects: those with moderate NPDR, no color defects ; and those with severe NPDR, 2 tritan, and 2 protan defects, and 1 deutan defect. CONCLUSIONS: In diabetic patients, TES of SCHT and SCCT was higher according to the severity of diabetic retinopathy. SCHT and SCCT were more useful than HRR test.

Acquried Dyschromatopsia in Women Workers in Shoe Manufacturing Who were Exposed to Organic Solvents / 대한산업의학회지

OBJECTIVES: This study was undertaken to investigate the relationship between color vision defects and occupational exposure to mixed organic solvents in women workers who were engaged in the shoe manufacturing industry. METHODS: A total of 173 women workers were involved in this study, 85 of whom were exposed to mixed organic solvents and were defined as the exposed group, and 88 workers comprised the non-exposed control group. The patients were questioned as to their drinking history, the year in which they were exposed and whether they had eye symptoms of blurred vision, eye fatigue, and eye irritation. The exposed workers in the shoe manufacturing factory were engaged in 3 work areas which were pasting, trimming, and cleaning. Their Color vision was assessed using the Hahn's double 15 hue test under standard illumination and their current and cumulative exposure levels were measured. RESULTS: The prevalence of color vision defect was 21.2% in the exposed group and 8.0% in the control group, and the blue-yellow defect was found to be 5.9 % in the exposed group. The logistic regression for the acquired dyschromatopsia and color confusion index showed that there were no variables that had significant relationships. Eye symptoms were more frequently developed in the exposed group. CONCLUSIONS: There is a possibility of developing color vision defects when workers are exposed to mixed organic solvents. However, the results of the color confusion index showed that there was no significant relationship to the cumulative exposure level, because of the low exposure level and high occupational turn over rate of the workers. Because the workers in the present study were exposed to low level solvents it will be necessary to study workers exposed to higher levels of organic solvents.