light inspection

We know that the retina of the human eye can sense the stimulation of visible light from the outside world and convert it into a nerve impulse to convey the light perception to the central vision of the brain. The methods of photodetection are: 1 darkroom photodetection. 2 dark adaptation meter inspection method. For the simple method, the examinee and the normal dark adaptation function examiner simultaneously enter the darkroom that can control the luminosity, and record the time in which the surrounding object can be distinguished in the dark room to roughly judge the dark adaptation function of the subject. Basic Information Specialist Category: Ophthalmic Examination Category: Other Inspections Applicable gender: whether men and women apply fasting: not fasting Tips: Serious people can't delay, they should be dealt with in time. Normal value The regulation of light perception mainly depends on the adaptive function of the retina. In addition, the amount of eye light is controlled by the change of the size of the pupil, and it can also play a partial adjustment role. The material basis for producing light perception is the visual pigment. Under the action of light, the visual pigment in the retinal sensor can produce photochemical changes and bioelectrical changes, thereby showing light and dark vision. Clinical significance Abnormal results Retinitis pigmentosa and vitamin A deficiency, dark adaptation function is reduced or lost. Need to check the patient whose population has been destroyed by the retina. Precautions Taboo before inspection: Serious cases can not be delayed, and should be handled in time. Requirements for inspection: Adjustment controls the luminosity. Inspection process 1 Darkroom photo-detection method: For the simple method, the examinee and the normal dark-adapted function examiner simultaneously enter the darkroom that can control the luminosity, and record the time in which the surrounding objects can be distinguished in the dark room, and judge the test roughly. Dark adaptation function. 2 Dark adaptation test: When checking, the patient sits in front of the darkroom machine, turns on the light, and lets the patient look at the milky glass plate in the instrument for 5 minutes, then turns off the light, and replaces the milky white plate with a black-lined partition plate. Strengthen the brightness on the board. When the patient sees the black and white lines, immediately tell the inspector that the examiner records this point on the meter and repeats it every 1-2 minutes. After that, it can be repeated for a long time, for a total of 1 hour. Finally, the points are connected into a curve, that is, a dark adaptation curve. Not suitable for the crowd Inappropriate crowd: Patients with inflammation of the eyes.