{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T16:59:01Z","timestamp":1783702741299,"version":"3.55.0"},"reference-count":27,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2020,8,26]],"date-time":"2020-08-26T00:00:00Z","timestamp":1598400000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002645","name":"Sangmyung University","doi-asserted-by":"publisher","award":["2019"],"award-info":[{"award-number":["2019"]}],"id":[{"id":"10.13039\/501100002645","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>As the use of electronic displays increases rapidly, visual fatigue problems are also increasing. The subjective evaluation methods used for visual fatigue measurement have individual difference problems, while objective methods based on bio-signal measurement have problems regarding motion artifacts. Conventional eye image analysis-based visual fatigue measurement methods do not accurately characterize the complex changes in the appearance of the eye. To solve this problem, in this paper, an objective visual fatigue measurement method based on infrared eye image analysis is proposed. For accurate pupil detection, a convolutional neural network-based semantic segmentation method was used. Three features are calculated based on the pupil detection results: (1) pupil accommodation speed, (2) blink frequency, and (3) eye-closed duration. In order to verify the calculated features, differences in fatigue caused by changes in content color components such as gamma, color temperature, and brightness were compared with a reference video. The pupil detection accuracy was confirmed to be 96.63% based on the mean intersection over union. In addition, it was confirmed that all three features showed significant differences from the reference group; thus, it was verified that the proposed analysis method can be used for the objective measurement of visual fatigue.<\/jats:p>","DOI":"10.3390\/s20174814","type":"journal-article","created":{"date-parts":[[2020,8,26]],"date-time":"2020-08-26T09:05:37Z","timestamp":1598432737000},"page":"4814","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["Experimental Verification of Objective Visual Fatigue Measurement Based on Accurate Pupil Detection of Infrared Eye Image and Multi-Feature Analysis"],"prefix":"10.3390","volume":"20","author":[{"given":"Taehyung","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Computer Science, Sangmyung University, Seoul 03016, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6504-3333","authenticated-orcid":false,"given":"Eui Chul","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Human-Centered Artificial Intelligence, Sangmyung University, Seoul 03016, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,8,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Vanderloo, L.M. (2014). Screen-viewing among preschoolers in childcare: A systematic review. BMC Pediatr., 14.","DOI":"10.1186\/1471-2431-14-205"},{"key":"ref_2","first-page":"1","article-title":"Computer vision syndrome (aka digital eye strain)","volume":"17","author":"Rosenfield","year":"2016","journal-title":"Optometry"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"388","DOI":"10.3341\/kjo.2016.0095","article-title":"Visual fatigue induced by viewing a tablet computer with a high-resolution display","volume":"31","author":"Kim","year":"2017","journal-title":"Korean J. Ophthalmol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1016\/j.apergo.2017.10.014","article-title":"Symptoms associated with reading from a smartphone in conditions of light and dark","volume":"68","author":"Antona","year":"2018","journal-title":"Appl. Ergon."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1111\/cxo.12453","article-title":"Viewing distance and eyestrain symptoms with prolonged viewing of smartphones","volume":"100","author":"Long","year":"2017","journal-title":"Clin. Exp. Optom."},{"key":"ref_6","unstructured":"Brandt, T., Stemmer, R., and Rakotonirainy, A. (2004, January 10\u201313). Affordable visual driver monitoring system for fatigue and monotony. Proceedings of the 2004 IEEE International Conference on Systems, Man and Cybernetics (IEEE Cat. No. 04CH37583), The Hague, The Netherlands."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1007\/s10286-002-0044-8","article-title":"Fractal analysis and recurrence quantification analysis of heart rate and pulse transit time for diagnosing chronic fatigue syndrome","volume":"12","author":"Naschitz","year":"2002","journal-title":"Clin. Auton. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1136\/oem.58.4.267","article-title":"Psychological factors and visual fatigue in working with video display terminals","volume":"58","author":"Mocci","year":"2001","journal-title":"Occup. Environ. Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1097\/01.ICL.0000101489.13687.9A","article-title":"Effect of povidone 2% preservative-free eyedrops on contact lens wearers with computer visual syndrome: Pilot study","volume":"30","author":"Guillion","year":"2004","journal-title":"Eye Contact Lens"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1016\/j.acra.2009.02.008","article-title":"Measurement of visual strain in radiologists","volume":"16","author":"Krupinski","year":"2009","journal-title":"Acad. Radiol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1","DOI":"10.5384\/sjovs.vol11i1p1-5","article-title":"Eye movements, convergence distance and pupil-size when reading from smartphone, computer, print and tablet","volume":"11","author":"Miranda","year":"2018","journal-title":"Scand. J. Optom. Vis. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1447","DOI":"10.1109\/TCE.2009.5278012","article-title":"Measuring eyestrain from LCD TV according to adjustment factors of image","volume":"55","author":"Lee","year":"2009","journal-title":"IEEE Trans. Consum. Electron."},{"key":"ref_13","unstructured":"Divjak, M., and Bischof, H. (2009, January 20\u201322). Eye Blink Based Fatigue Detection for Prevention of Computer Vision Syndrome. Proceedings of the MVA 2009 IAPR Conference on Machine Vision Applications, Yokohama, Japan."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1016\/S0262-8856(99)00053-0","article-title":"Pupil detection and tracking using multiple light sources","volume":"18","author":"Morimoto","year":"2000","journal-title":"Image Vis. Comput."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Bozomitu, R.G., Pasarica, A., Cehan, V., Rotariu, C., and Barabasa, C. (2015, January 6\u201310). Pupil centre coordinates detection using the circular Hough transform technique. Proceedings of the 2015 38th International Spring Seminar on Electronics Technology (ISSE), Eger, Hungary.","DOI":"10.1109\/ISSE.2015.7248041"},{"key":"ref_16","unstructured":"Leimberg, D., Vester-Christensen, M., Ersb\u00f8ll, B.K., and Hansen, L.K. (2005, January 10\u201311). Heuristics for speeding up gaze estimation. Proceedings of the Svenska Symposium i Bildanalys, Malm\u00f8, Sweden."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"411","DOI":"10.1109\/TBME.2010.2087330","article-title":"Iris center corneal reflection method for gaze tracking using visible light","volume":"58","author":"Sigut","year":"2010","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_18","unstructured":"Schneider, E., Dera, T., Bard, K., Bardins, S., Boening, G., and Brand, T. (2005, January 12). Eye movement driven head-mounted camera: It looks where the eyes look. Proceedings of the 2005 IEEE International Conference on Systems, Man and Cybernetics, Waikoloa, HI, USA."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"55948","DOI":"10.1109\/ACCESS.2018.2869624","article-title":"Eye fatigue assessment using unobtrusive eye tracker","volume":"6","author":"Wang","year":"2018","journal-title":"IEEE Access"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1186\/s12938-019-0731-5","article-title":"Assessment of eye fatigue caused by head-mounted displays using eye-tracking","volume":"18","author":"Wang","year":"2019","journal-title":"Biomed. Eng. Online"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"KHAN, W., Hussain, A., Kuru, K., and Al-Askar, H. (2020). Pupil Localisation and Eye Centre Estimation Using Machine Learning and Computer Vision. Sensors, 20.","DOI":"10.3390\/s20133785"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"834","DOI":"10.1109\/TPAMI.2017.2699184","article-title":"Deeplab: Semantic image segmentation with deep convolutional nets, atrous convolution, and fully connected crfs","volume":"40","author":"Chen","year":"2017","journal-title":"IEEE Trans. Pattern Anal. Mach. Intell."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Fuhl, W., Kubler, T., Sippel, K., Rosenstiel, W., and Kasneci, E. (2015, January 2\u20134). Excuse: Robust pupil detection in real-world scenarios. Proceedings of the International Conference on Computer Analysis of Images and Patterns., Valletta, Malta.","DOI":"10.1007\/978-3-319-23192-1_4"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"554","DOI":"10.1097\/00006324-195011000-00003","article-title":"Visual fatigue","volume":"27","author":"Simmerman","year":"1950","journal-title":"Optom. Vis. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1037\/h0036529","article-title":"Pupillography in industrial fatigue assessment","volume":"59","author":"Geacintov","year":"1974","journal-title":"J. Appl. Psychol."},{"key":"ref_26","first-page":"1318","article-title":"Assessment of fatigue by pupillary response","volume":"80","author":"Murata","year":"1997","journal-title":"IEICE Trans. Fundam. Electron. Commun. Comput. Sci."},{"key":"ref_27","first-page":"203","article-title":"Flight guardian: Autonomous flight safety improvement by monitoring aircraft cockpit instruments","volume":"15","author":"KHAN","year":"2018","journal-title":"J. Aerosp. Inf. 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