Basic Study of an Assisting Method for Visual Information Perception among Low Vision Patients by Means of Gazing Information Feedback

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In close collaboration with the researchers, two kinds of algorisms were developed to control the character size automatically. The implemented algorisms are as follows;(1) The character is magnified if the standard deviation of the gazing points for the past five frames exceeds a certain threshold revel. On the contrary, character size is reduced intentionally by closing the eyes for more than 30 seconds.(2) The character size is magnified if the subject makes his eyes thin more than the predetermined threshold level. The size is reduced in the same way as the first algorism.By using the news article printed on A4-sized sheet, validity of the first algorism was investigated for seven aged persons suffering from cataract and seven healthy students with low visual power. The results showed that both groups were able to read the document with the same speed by using the developed adaptive magnifier.The second algorism was evaluated by subject's effort of making his eyes thin when he felt difficulty of reading the document. The subjects are ten young students without suffering from eye diseases but with low eyesight and seven young students with visual disabilities. The average reading speed of students with visual disabilities was slower than that of subjects without visual disabilities. The difference may come from the usual status of opening of the eyes in the person with disabilitiesUsefulness of the adaptive viewer was confirmed experimentally. By combining some useful algorisms such as above, the developed viewer will work more appropriately.