examination of eyes
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Visual function tests including visual psychophysics (including eyesight, dark adaptation, color vision, contrast sensitivity, etc.) and visual electrophysiology two class methods. 1. Acuity (1) distance vision inspection : ① visual acuity chart. China is a common international standard vision chart, the visual acuity meter used for low vision examination. Visual light on the need of adequate or artificial lighting, were to be examined from the visual distance of 5 m, 1.0 make this trip with the seizure focus on the same level. Two separate checks from top to bottom that superscript characters as opening direction, said on the minimum standard as the name, and his party on record. For example, 1.2 right eye, left eye 1.5. Normal distance vision for the 1.0 standard. ② able to distinguish visual 0.1 will be able to check who was approached visual gradually until identified 0.1 visual target date. According approached the distance, according to a formula V = d / D × 0.1 calculation eyesight. V for vision, D-normal glance, the bank distance, d were to be seized to see that the distance For example, 3 m 0.1 can see, the vision for the 3 / 5 x 0.1 = 0.06. ③ index. Approaching able to distinguish a 0.1 m, then digitized finger. Who was seized backlight old, from the fingers pointed minded rough. If the 50 cm can tell index, visual index = / 50cm. ④ manually. Fingers nearly 5 cm to the immediate confused, it was replaced in the immediate seizure swing around to record the distance to see, If manual / 20cm. ⑤-flu. Not see the manual, in a dark room with candles or flashlights irradiation eyes. To see the bright light flu, could not see the sense of disgrace. And to make light positioning, eye to the front watch fixed, and the lighting in a m distance, check in several directions. (2) inspection of myopia : a common standard table or myopia of Jaeger’s myopia tables. Adequate lighting in the under 30 cm away from the eyes, check eyes, or J1 standards such as myopia of Table 1.0. If patients ametropia, should be allowed to change the distance between, for example, J1 (20 cm), changing the distance can be recorded. 2. When the dark-adapted eyes from bright light into the dark, could not see anything at first, with the photosensitive after the increase, gradually be able to recognize a dark object. Dark adaptation of the former, the latter for adaptation. Dark adaptation inspection two ways : one is to contrast, another is a dark adaptation screening. In retinitis pigmentosa and vitamin A deficiency diseases such as malnutrition, dark adaptation reduction or loss of function. 3. Color vision for transport, construction, art, chemistry, medicine and other work must have normal color vision, This is military service, employment and schooling before the medical examination necessary for the project. Color blindness test : at present color perception test, commonly used several methods below. (1) at the same color map test : leave the same color map commonly known as the Blind, with the same brightness and color easily confused constitute Dot Graphics, Digital, normal color to distinguish short, color-blindness and can only judge to chiaroscuro. Inspection under natural light, the distance between 0.5m and should be seized in five seconds to read out. (2) the selection of map color embroidery floss France : Color map! Knitting wool in a pile mixed with various colors of embroidery floss map, in a certain color requirements which were seized were singled out for their identical or similar, but also to enable the seizure will be a color. (3) Other : FM-100 color test, D-15 pilot sites color and color microscopy. Color barriers divided into congenital or acquired. Normal for the three color TV, compared with the weak color abnormal color TV, red, green, blue single-color blindness were two color TV, full color blindness, as were the same color. 4. When vision is the vision to the eye as the solid front is fixed, see the space. Can be divided into peripheral vision and center vision. Fundus examination of vision and visual way disease is important. Peripheral vision inspection simple contrast and peripheral vision or two methods. Vision inspection center with flat screen vision, the central inspection within 30 ° field of vision. 5. Contrast Sensitivity Contrast sensitivity is the visual system of identification of objects of different sizes frequency space required for the objects on the surface of the contrast between black and white (contrast), the visual system for the evaluation of different sizes of the objects identified, it is a new visual function quantitative methods. 6. Elcetrophysiological visual process is biological activity, from the retinal-induced chemical reaction, Finally into electricity, by the nerve to the visual cortex of the brain transfer. By measuring the visual biological activity, as a non-damaging to the objective examination of the visual system for disease diagnosis, Clinical identification and prognosis. Common eye — maps, electroretinogram, visual evoked potentials. |