Chromatest Computer Color Vision Test And Electrophysiology Of Vision Test Used In Color Perception Deficiencies

Color perception is one of the three functions(light perception,form perception,color perception) of visual system. Color perception deficiencies caused by genetic or acquired agents often hinders people from perceiving this colorful world normally. Patients with color perception deficiency meet many restrictions in the choice of different occupations or careers, especially in the field of flying concerning life security. In the aspect of the subjective test of color perception: Lantern is generally deployed abroad as chromatoscopy for professional bolting, utilizing simple combination of luminaries of three different colors, whose mis-inspect rate is high, as a result, some individuals with color perception discrepancy could successfully pass it. An air accident happened in Jul.2002, which was suspected to be connected with color perception of the pilot and drew great attention of Federal Aviation Agency(FAA) and National Transportation Safety Broad(NTSB). With the application of modern computer technology, revolutionary changes have taken place within capsule cabin and the display mode of navigation, leading our focus on the need for color perception to the field of flying and traffic control, which inspires widely debate and investigation about the connection between color and aviation safety in recent years. Special subjects are reported in the annual US Aerospace Medicine Association, which concerns the device, standard and influencing factors of chromatoptometry. FAA has unveiled fresh policy about the special checking method of color perception discrepancy in 2008, at the same time, its computer-assisted chromatoptometry for air controller is under authentication, and the Colour Assessment and Diagnosis(CAD) developed by the UK London University will be authenticated by FAA recently. Nowadays, chromatoptometry in domestic health examination including health examination in pilot recruitment, still generally deploys color perception test book based on principle of pseudoisochromatic, which utilizes surface color. Since surface colors are mostly compound colors, which are impacted greatly by background and unstable in the aspects of color hue, brightness and degree of saturation; more importantly, for the sake of non-elimination of the accurate problems existed in pseudoisochromatic plates test itself or subjects'retention on purpose, the one with color perception deficiency could successfully pass the chromatoptometry. In addition, the degree of color perception discrepancy parallels with the variation of state of the illness of organum visual which generates acquired color anomalopia. As a result, a special test is needed to provide some sensitive diadynamic criteria for the early diagnosis of some important oculopathy such as age-related maculopathy and diabetes mellitus, which is to be applied to annual health examination of staff in field of flying to ensure the air safety. So, it's quite important to consummate the subjective test of color perception. In the aspect of the objective test of color perception: Research in the value of color VEP in chromatoptometry, which is characterized in objective quantitate, has been put into effect since the 90th decade in last century. For this reason, we have carried out research in color and graph resupination VEP of equal brightness, of which we want to comprehend the waveshape within normal individuals or the ones with inborn protan color perception discrepancy to provide some initial evidences for the objective test of color perception.In respect of the importance and non-consummate condition of chromatoptometry, and the restrictions of our knowledge about color perception mechanism, it's quite necessary to do some further research work in this field.Method1. During the health examination in pilot recruitment conducted by Northwest Civil Aviation Bureau in 2008, 134 male volunteers(268 eyes) are recruited to take the 6.5o optotype of ChromaTest. Then we delineate the characteristic of frequency distribution of color perception contrast sensitivity within healthy youths and calculate normal reference value of contrast sensitivity of protan and tritan color perception. The normal value of protan color perception contrast sensitivity will be taken as the diagnostic criteria of inborn color anomalopia, and that of tritan color perception as early auxiliary diagnosis for important oculopathy.2. 32 male volunteers(64 eyes) with protan color perception discrepancy and 12(24 eyes) with normal color perception take the color and graph resupination VEP of equal brightness test under three stimulus modalities of Red-Grey,Green-Grey and Red- Green. Then we analyze the characteristic of subjects'waveshapes of the two groups and make comparison between them. Result1. Normal values of ChromaTest color perception contrast within healthy youths: 2. Waveshapes of figure evoked potential in two groups are well recorded under different stimulus. All P1 latent periods in two groups exceed 100ms among three modalities, and the latent period of Red-Grey stimulus persists longer than the other two. Variation of P1 latent periods between volunteers with protan color perception discrepancy and with normal color perception has no statistically significance, while variation of P1 ridges has, and the latter is higher than the former. Consequences are as follow: Conclusion1. This research helps get the range and general characteristics of protan and tritan values of 134 healthy youths, add a supplement of reference value to the Asian race, and consummate the subjective test of color perception. More importantly, it provides the primitive evidence for the application of ChromaTest as the associated color sense inspection item in health examination in pilot recruitment and the auxiliary diagnosis in early stage of some important oculopathy.2. Color and graph resupination VEP of equal brightness under three stimulus modalities all educe N1,P1,N2 waves ideally. Values of P1 ridges are higher in the group with normal color perception than those with protan discrepancy, which provides initial evidences for the objective test of inborn protan color anomalopia.