Background  The diagnosis of congenital protan/deutan color vision deficiency (CVD) is still problematic, with inaccurate classification and unclear severity.

  Objective  To evaluate the ability of Yu's color blindness test (Yu’s) book and Color Blind Check (CBC) score for classification and severity division of patients with CVD compared to Fornsworth Munsell-100 hue test (FM-100), so as to improve the clinical diagnosis level and provide reference for its treatment.

  Methods  Yu 's book, CBC score and FM-100 were used to detect patients with CVD who were admitted to the Third Medical Center of Chinese PLA General Hospital from February to July in 2022. Compared with FM-100, the diagnostic efficacy and classification error rate of the CBC score and Yu's book were evaluated.

  Results  Among the 173 patients, those with abnormal red and green perception were 1.2% and 12.7% by Yu 's book, 36.4% and 62.4% by CBC score, 19.1% and 65.9% by FM 100. The results of the three methods of severity were similar. Taking FM-100 as the gold standard, the sensitivity and specificity of Yu 's book and CBC score of CVD severity division were 91.3% and 38.5%, 92.5% and 46.2%, respectively, and the area under curve was 0.712 and 0.604, respectively. The sensitivity and specificity of Yu 's book and CBC score of CVD classification were 0 and 15.8%, 75.8% and 78.9% for protan CVD, and the Kappa values were -0.125 and 0.490. The sensitivity and specificity for deutan were 15.8% and 0, 78.9% and 75.8%, with Kappa values as -0.125 and 0.490. The result of average detection time was as follows: Yu 's book<CBC score<FM-100.

  Conclusion  Yu 's book can quickly screen for CVD and preliminarily determine the severity, and CBC score has a certain ability to assess the classification and severity with stable results, which is short time-consuming and difficult for cheating, with certain clinical application prospects.