Wavelength dependency of the critical flicker-fusion frequency: therapeutic 40 Hz light source in Alzheimer’s disease

2021 ◽  
Author(s):  
Marcus S. Carstensen ◽  
Martin Thorning-Schmidt ◽  
Mikkel Agger ◽  
N. Mai Nguyen ◽  
Jes Broeng ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Light Source ◽  
Critical Flicker Fusion ◽  
Flicker Fusion Frequency ◽  
Fusion Frequency ◽  
Critical Flicker Fusion Frequency ◽  
Flicker Fusion ◽  
40 Hz

scholarly journals Critical Flicker Fusion Frequency: A Narrative Review

Medicina ◽  
2021 ◽  
Vol 57 (10) ◽  
pp. 1096
Author(s):  
Natalia D. Mankowska ◽  
Anna B. Marcinkowska ◽  
Monika Waskow ◽  
Rita I. Sharma ◽  
Jacek Kot ◽  
...  
Keyword(s):  
Visual Processing ◽  
Current Knowledge ◽  
Minimal Hepatic Encephalopathy ◽  
Future Research ◽  
Critical Flicker Fusion ◽  
Flicker Fusion Frequency ◽  
Fusion Frequency ◽  
Critical Flicker Fusion Frequency ◽  
Model Studies ◽  
Flicker Fusion

This review presents the current knowledge of the usage of critical flicker fusion frequency (CFF) in human and animal model studies. CFF has a wide application in different fields, especially as an indicator of cortical arousal and visual processing. In medicine, CFF may be helpful for diagnostic purposes, for example in epilepsy or minimal hepatic encephalopathy. Given the environmental studies and a limited number of other methods, it is applicable in diving and hyperbaric medicine. Current research also shows the relationship between CFF and other electrophysiological methods, such as electroencephalography. The human eye can detect flicker at 50–90 Hz but reports are showing the possibility to distinguish between steady and modulated light up to 500 Hz. Future research with the use of CFF is needed to better understand its utility and application.

scholarly journals HYGIENIC EVALUATION OF THE FONT DESIGN OF ELECTRONIC TEXTS PRESENTED ON A LAPTOP

2019 ◽  
Vol 98 (12) ◽  
pp. 1402-1407
Author(s):  
Vladislav R. Kuchma ◽  
S. V. Sankov ◽  
N. K. Barsukova
Keyword(s):  
Educational Process ◽  
Critical Flicker Fusion ◽  
Visual Analyzer ◽  
Flicker Fusion Frequency ◽  
Fusion Frequency ◽  
Critical Flicker Fusion Frequency ◽  
Font Design ◽  
Psychophysiological State ◽  
The Impact ◽  
Flicker Fusion

Introduction. Currently, in connection with the large-scale introduction of the electronic educational resource in the educational process, it is especially relevant to search for optimal characteristics of presenting information on screens, taking into account the specifics of the electronic devices and age-related physiological features of the users’ visual system. The aim of the study was a physiological hygienic assessment of the impact of the font design of e-texts, presented on a laptop, on the psychophysiological state of students in grades 10-11. Material and methods. Psychophysiological testing of 43 schoolchildren in grades 10-11 without pathology of the vision organ was carried out on the NS-Psychotest complex, including the method of critical flicker fusion frequency to assess the state of the central part of the visual analyzer and the response to a moving object to determine the degree of the balance in nervous processes. The influence of reading illogical texts typed by a school headset was studied with a font size of 14, 12 and 10 points and a one-time reading of 200, 400 and 600 characters. Laptop Lenovo IdeaPad 720S-15 was used for the presentation of information. Results. High-grade schoolchildren were established to have the initial fatigue both of the visual analyzer and the nervous system as a whole. Boys showed better indices of the critical flicker fusion frequency than girls. Most schoolchildren had a balanced type of the inhibition and excitement processes. Methods of presenting information in electronic textbooks were shown to affect the psychophysiological state of high schoolchildren and may carry risks to their health. The hygienically rational design of electronic educational texts promotes the optimization of the psycho-functional state of the high schoolchildren’s body. Conclusion. The obtained results allow substantiating hygienic requirements for the font design of e-learning publications at the third stage of education.

Reply: Commentary on using critical flicker fusion frequency to measure gas narcosis

2021 ◽  
Vol 51 (2) ◽  
pp. 228-229
Author(s):  
Xavier CE Vrijdag ◽  
◽  
Hanna van Waart ◽  
Jamie W Sleigh ◽  
Simon J Mitchell ◽  
...  
Keyword(s):  
Critical Flicker Fusion ◽  
Flicker Fusion Frequency ◽  
Fusion Frequency ◽  
Critical Flicker Fusion Frequency ◽  
Flicker Fusion

scholarly journals Az IMEA ADR III kritikus fúziós frekvenciavizsgáló eszközzel végzett mérések reprodukálhatóságának vizsgálata

2016 ◽  
Vol 157 (27) ◽  
pp. 1079-1086
Author(s):  
Orsolya Angeli ◽  
Dániel Sándor Veres ◽  
Zoltán Zsolt Nagy ◽  
Miklós Schneider
Keyword(s):  
Critical Flicker Fusion ◽  
Young Population ◽  
Flicker Fusion Frequency ◽  
Measuring Device ◽  
Fusion Frequency ◽  
Critical Flicker Fusion Frequency ◽  
Measurement Results ◽  
The Mean ◽  
Frequency Threshold ◽  
Flicker Fusion

Introduction: Measurement of central critical flicker-fusion frequency is a common screening test for eye diseases and additionally it can serve as a useful diagnostic test in numerous neurological and internal diseases. The test might also be used for monitoring purposes. Aim: The aim of the authors was to evaluate a digital central critical flicker-fusion frequency measuring device (IMEA ADR III) in 30 young, healthy Hungarian subjects. Method: After a general ophthalmological screening examination, monocular central critical flicker-fusion frequency was measured with four colours. Measurements were carried out on two separate days in three sessions under standardized conditions. Intrasession, intersession and intervisit variabilities, differences in central critical flicker-fusion frequency using the four colours and the effect of certain other influencing factors were determined. Results: There were no statistically significant differences between sessions in the mean and standard deviation of the measurement sets. The central critical flicker-fusion frequency threshold for red colour was significantly lower than for other colours, and the threshold for blue colour was significantly lower than for green. There were no significant differences regarding sex, age, iris colour, and smoking indicating that these factors did not influence the central critical flicker-fusion frequency threshold in these subjects. Conclusions: Measurement results with the device are reliable and reproducible in healthy, young population in separate sessions. Orv. Hetil., 2016, 157(27), 1079–1086.

scholarly journals Asthenopia: Diagnosis, Tatalaksana, Terapi

2021 ◽  
Vol 1 (2) ◽  
pp. 97
Author(s):  
Pande Putu Arista Indra Pratama ◽  
Komang Hendra Setiawan ◽  
Ketut Indra Purnomo
Keyword(s):  
Literature Review ◽  
Critical Flicker Fusion ◽  
Flicker Fusion Frequency ◽  
Fusion Frequency ◽  
Critical Flicker Fusion Frequency ◽  
Flicker Fusion

Asthenopia (kelelahan mata) merupakan sekumpulan gejala berupa permasalahan pada penglihatan (visual), mata (okular), dan muskuloskeletal yang umumnya terjadi hilang timbul. Keluhan ini sering muncul akibat pengaruh penggunaan perangkat digital dalam waktu yang lama terutama lebih dari 6 jam perhari. Penderita asthenopia secara global mencapai 60 juta orang yang didominasi usia muda. Gejala asthenopia yang paling sering dirasakan adalah keluhan mata kering, kesulitan dalam memfokuskan objek, mata tegang, mata lelah, dan sakit kepala. Diagnosis asthenopia dapat dilakukan secara subjektif dengan menggunakan kuesioner standar ataupun secara objektif dengan pemeriksaan lanjutan. Pemeriksaan yang dapat dilakukan berupa pengukuran Critical Flicker-fusion Frequency (CFF), pengukuran frekuensi berkedip, kemampuan akomodasi, serta refleks cahaya dan ukuran pupil yang dapat memberikan gambaran lebih jelas ke arah asthenopia. Tatalaksana dan terapi pada asthenopia diberikan untuk meredakan gejala dan mengatasi penyebabnya seperti terapi untuk mengatasi mata kering, koreksi gangguan refraksi, terapi gangguan akomodasi dan vergensi, dan penggunaan kacamata filter cahaya biru. Walaupun asthenopia terjadi secara hilang timbul, penyakit ini dapat menjadi menetap dan berkembang menimbulkan keluhan permanen. Artikel ini ditulis berdasarkan hasil literature review dari penelitian terkait diagnosis, tatalaksana, dan terapi asthenopia yang sudah dipublikasi. Penulisan artikel ini diharapkan dapat dijadikan acuan dalam menindaklanjuti kasus asthenopia sehingga prevalensi dan insidensinya dapat ditekan.

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