FIELD: medicine.
SUBSTANCE: invention pertains to medicine. The subject is exposed to light flitting, emitted by light emitting diodes with preset initial frequency. Light flitting frequency of the first diode remains unchanged, light flitting frequency of the second diode is increased presenting increment frequency, or decreased presenting decrement frequency. During the first stage of the measurements frequency of light flitting of the second light emitting diode is first continuously increased at the speed of 0.5 Hz/s, until the subject subjectively detects difference between the presented frequencies and registers thereat the first increment frequency of light flitting. Then frequency of light flitting of the second light emitting diode is continuously decreased at the speed of 0.25 Hz/s, until the subject detects the point, when presented light flittings do not differ and registers thereat the second increment frequency of light flitting. Thereafter frequency of light flitting of the second diode is discretely increased in increments of 0.1 Hz, till the subject registers differential threshold of the presented light flitting and registers the third increment frequency of light flitting. Threshold value is computed as the difference between the third increment and initial frequencies of light flitting. During the second stage of measurements having presented light flitting at the preset initial frequency, the latter is first continuously decreased at the same constant speed of 0.5 Hz/s, until the subject subjectively detects difference between the presented frequencies and registers thereat the first decrement frequency of light flitting. Then frequencies of light flitting of the second diode are increased at the same constant speed of 0.25 Hz/s until the subject detects the point when the presented light flittings do not differ and registers thereat the second decrement frequency of light flitting. Thereafter frequencies of light flitting of the second diode are discretely decreased at increments of 0.1 Hz until the subject detects the differential threshold of the presented light flitting. Differential threshold value is computed as the difference between the third decrement and initial frequencies of light flitting. Pass band of the spatial frequency channel is defined as the arithmetic mean value of differential threshold values of light flitting frequencies, computed during the first and the second stages of the measurements.
EFFECT: method makes it possible to detect pass band of the spatial frequency channel of the vision system by presenting two flitting lights using light emitting diodes to the subject.
2 dwg, 1 ex
