Nagel color vision microscopy

Nagel color vision examination, color vision mirror is a spectral instrument designed according to the principle of proper mixing of red and green light into yellow light. 1 The examinee sits in front of the instrument and looks at the observation hole. A circular disc is visible, with the upper half being red or green and the lower half being yellow. 2 The examiner adjusts the monochrome knob on the right side to adjust the brightness of the yellow light to the 12.5 scale, and the examinee rotates the left color mixing knob until the color and brightness of the upper and lower halves are exactly the same. Basic Information Specialist Category: Ophthalmic Examination Category: Other Inspections Applicable gender: whether men and women apply fasting: not fasting Tips: Forbidden medication before check. Patients with inflammatory eyes are not suitable for this test. Normal value The field of view seen from the color vision mirror is divided into two parts, one is yellow with a certain wavelength; the other is a mixture of red and green. Yellow has only a change in brightness, and the red-green mixture ratio is variable. Clinical significance Abnormal results: 1 Green and yellow equals the founder is congenital green weak, congenital full color weak, acquired red and green weak. 2 Red and yellow equals found that the congenital red is weak, the congenital full color is weak, the rod-color perception, and the acquired red and green are weak. 3 green and yellow equal, red and yellow equals are established inborn red blind and green blind, congenital full color weak, cone-color perception. 4 Green and yellow equal and red and yellow equals are not established in normal eyes, mild congenital red and green weak, congenital and acquired full color weak, acquired red and green weak, non-shaped rod-color perception. Need to check the crowd color is not normal. Precautions Forbidden before examination: use drugs indiscriminately. Requirements for inspection: The instrument should be clean and well lit. Inspection process 1 The examinee sits in front of the instrument and looks at the observation hole. A circular disc is visible, with the upper half being red or green and the lower half being yellow. 2 The examiner adjusts the monochrome knob on the right side to adjust the brightness of the yellow light to the 12.5 scale, and the examinee rotates the left color mixing knob until the color and brightness of the upper and lower halves are exactly the same. Make a note of the reading and the normal equal point is about 70 marks. 3 The examiner turns the color mixing knob to 0 degrees, and the subject rotates the monochrome knob. Each time the mixing knob is added 10°, the examiner rotates the monochrome knob until it is equal, records its equal point, repeats three times, and takes the average value. 4 Record each result in a dedicated form and draw an equal curve. Not suitable for the crowd Inappropriate crowd: Patients with inflammation in the eyes.

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