Introduction: In esthetic dentistry, COLOR matching ability is one of the influencing factors in treatment. To achieve this goal, matching the COLOR of restoration with natural teeth is essential. The objective of this study was to determine the frequency of COLOR VISION DEFECT in students of Mashhad Dental School and evaluation of related factors.Materials & Methods: In this descriptive analytical study, 356 students of Mashhad Dental School were evaluated. Demographic data including age, gender, COLOR VISION DEFECT in relatives, use of glasses and contact lenses, refractive errors (myopia, hypermetropia and astigmatism) were documented in the designed questionnaire. To determine the impaired COLOR VISION, Ishihara diagnostic test was used. Statistical analysis of SPSS version 19 was performed using Chi-Square and Logistic Regression tests at the significance level of 0.05%.Results: COLOR VISION DEFECT was found in 6% (12 persons) of male students while none of the females were affected. All affected persons were red-green COLOR blind and strong deutan. There was a significant relationship between COLOR VISION deficiency and history of COLOR VISION DEFECT in relatives (P=0.03), so that 25% (3 persons) of affected persons had a positive family history of COLOR VISION DEFECT.Conclusion: Considering the frequency of COLOR VISION DEFECT in the present study as well as the importance of COLOR matching in dental treatments and because most affected persons are unaware of this DEFECT, COLOR VISION tests seem necessary.

COLOR VISION deficiency (CVD) is a DEFECT of VISION with disability to distinguish COLORs. COLOR VISION deficiency can be divided into the two categories, congenital and acquired. Congenital COLOR VISION deficiency divided into anomalous trichromacy, dichromacy and monochromacy. The most common congenital CVD was deuteranomalous that mode of inheritance is X linked recessive occurring mostly in males. Acquired CVD can occur as a direct result of illness or any related medicine. COLOR perception changes in acquired CVD may be secondary to primary ocular disease, drug side effect, or serious systemic disease such as diabetes. Dystrophy of cone, types of maculopathy, crystalline lens changes associated with aging, diabetes, glaucoma, optic nerve diseases and traumatic brain injuries can cause CVD. For acquired CVD, type of DEFECT may not be easy to classify; nevertheless, predominantly is tritanopia and type and severity of the DEFECT fluctuates during of disease. It has been suggested that human evolution to industrialized civilization has led to an increased prevalence of CVD in most population. An acquired CVD can reflect a deficiency in COLOR information processing at anywhere along the related visual pathway, from the photoreceptors to the cortex. Sometimes, assessment of COLOR VISION can be helpful to detect a visual impairment in early stages.

Purpose: To evaluate COLOR VISION in axial high myopia. Method: In this cross-sectional study, all patients aged 17 to 40 years, with refractive error of 6.00 D or more and anteroposterior (AP) diameter of 26 mm or more were included. Cases with any lens opacity, glaucoma, diabetes mellitus, and optic nerve disease were excluded. During COLOR VISION examination, individuals wore the correction and COLOR VISION was tested monocularly with farnsworth panel D-15. Results: Forty patients (76 eyes) with axial high myopia were studied. Mean spherical error was -11.32 D and mean cylinder was -2.34 D. Overall 26 eyes (34.2%; 95% CI, 23.5-44.9) had COLOR VISION DEFECTs including 24 eyes (84.6%) with tritan (blue-yellow) DEFECT, 3 eyes (11.5%) with deutan (green) DEFECT, and one eye (3.9%) with protan (red) DEFECT. About 57% of the eyes with AP diameter more than 29 mm and 25.4% of the eyes with AP diameter of29 mm or less had COLOR VISION DEFECT (R.R=2.2, P<0.02). About 52% of the eyes with refractive power of more than -12.00 D and 24.5% of the eyes with myopic refraction of -12.00 D or less had DEFECTive COLOR VISION (R.R=2.1, P<0.02). About 44% of the eyes with visual acuity less than 20/30 and 12.5% of the eye with visual acuity of20/30 or more had DEFECT in COLOR VISION test results (R.R=3.5, P<0.0l). Conclusion: In axial high myopia there is: 1) COLOR VISION DEFECT, mostly with a tritan DEFECT, and 2) correlation between the length (AP diameter) of the eye and DEFECTive COLOR VISION.

COLOR VISION is one of the most important functions of visual system that has fundamental and considerable roles in visual data gathering, perceptual VISION, visual information processing, correlation between different visual information and correlation with other senses. To investigate COLOR VISION, we need to understand COLOR VISION mechanism with respect to psychophysical findings. In this subject, retinal COLOR VISION mechanism and central nervous system play important function with each other, however, in different and parallel processes. For understanding this mechanism, we should focus on neuro-anatomy and neurophysiology of retinal cone cells, other retinal cells, COLOR visual pathways, visual cortex, higher-order visual areas, and mechanisms that underlie the transformation from stimulus to perception. Most significant involved mechanism in COLOR VISION is the COLOR opponency in visual system. Additionally, different types of neurons with its connections and other factors like contrast, luminance, brightness, boundary COLOR and surround region COLOR, COLOR constancy, and etc., have many effects on COLOR perception. In this systematic review, peer reviewed articles that published in PubMed from January 1970 to January 2015 have been searched, assessed and interpreted. Additionally, in this review, quantitative and qualitative peer reviewed evidences with regard to inclusion and exclusion criteria, have been gathered, summarized, discussed and concluded. The purpose of this study is to review the structure and function of visual system in COLOR VISION.

Purpose: To determine the prevalence of blue-yellow COLOR VISION DEFECTs among diabetics at Farabi and Shariati Hospitals during 2001.Methods: This cross-sectional study was conducted on diabetics referred to us. We excluded patients whom were affected by cataract, age-related macular degeneration, optic neuritis, optic atrophy, glaucoma, or vitreous hemorrhage or other retinal disease; and also whom had undergone laser therapy. COLOR VISION was examined by Farans worth D-15 and Lanthony D-15. Role of age, sex, visual acuity, duration of diabetes mellitus, stage of retinopathy, and macular edema were assessed.Results: Of 120 diabetics, 33.5% were male and 64.4% were female. Mean age (SD) was 48.5 (15.1) years. There was 22.4% and 47.6% COLOR VISION DEFECTs according to Farans worth D-15  and Lanthony D-15 tests, respectively. There was a positive association between age, duration of diabetes mellitus, visual acuity, stage of retinopathy, and macular edema with the COLOR VISION DEFECT, but the DEFECT had no association with sex.Conclusion: Blue-yellow COLOR VISION DEFECT has a significant prevalence among diabetics.

Acquired COLOR deficiency in the tritan axis in Parkinson"s disease has already been reported, manifesting itself as impaired performance in various visual tasks. However, its clinical significance has always been controversial. In this study we evaluated the performance of Parkinson"s disease patients in Lanthony 15-desaturated clinical test and for the first time, compared it with the standard Farnsworth-Munsell 15-dichotomous test, in order to determine the clinical value of the COLOR VISION deficiency in these shorter tests and their relationship with other factors such as age, duration and severity of the disease, and the presence of signs and symptoms of depression and hallucinations. This blind case-control study was performed on 39 definitely diagnosed patients (of which 14 patients were excluded because of confounding variables) and 25 sex and age-adjusted controls in a neurologic referral center. The subjects were selected by consecutive sampling. Eleven patients in Famsworth-Munsell and 3 patients in Lanthony showed normal function, however, overall patients had significantly weaker performance than controls (P-value=0.003 and 0.000 for FM and Lanthony respectively). The pattern of responses in Lanthony was consistent with a mild tritanomalia and had a significant correlation with the severity of motor signs and symptoms (Spearman coefficient=0.44, P-value=0.027). The weaker correlation of COLOR deficiency with age in patients (Spearman coefficient=0.42) in comparison with controls (Speannan coefficient=0.60) also signifies the role of the pathophysiology of the disease. We concluded that COLOR deficiency is a clinically significant visual dysfunction in patients with Parkinson"s disease.