Design of the eye-catcher

Abstract

“Watch the birdie” Says the photographer to catch the attention of the child for a few seconds. My assignment was to design the “bird”. In this graduation project the photographer, the camera, the child to be photographed and the bird were replaced by the orthoptist, a device to measure angles of cross-eyedness (strabismus), the patient to be measured and the the “eye-catcher”. Strabismus Crossed eyed people can be operated on. The current trend is to perform this surgery in very young children which leads to a demand to also perform the measurement of the angle of strabismus at an early age. My assignment was to design an instrument aimed at children of age group 6 months to 3 years that can draw and keep their attention, and could lead their gaze into different directions during testing. Current method to measure strabismus angles Currently, the measurement of the angle of strabismus is performed manually by an orthoptist. During this test, the orthoptist is responsible for drawing the child’s attention. This additional task of entertaining complicates his work. DAISY- automatic strabismus angle measurement At the faculty of Mechanical Engineering of the Delft University of Technology, an instrument is being developed, the DAISY, which can measure the angle of strabismus in crossed eyed people automatically. This method requires of the patient to look in different directions of gaze for about 1 second per direction. In testing adults, this is no problem, whereas in working with young children this can be problematic. The essence of this project was therefore twofold: - To establish how to draw a child’s attention. - To establish how to have a child look into different directions of gaze. The eye-catcher and its functioning The eye-catcher will in the future be functioning together with the DAISY. Because of the fact that the latter is still being developed, it is not yet entirely clear what it’s looks and exact method of functioning will be like. What can be assumed as a basic starting point for the development of the eye-catcher is that a child’s attention needs to be drawn during a period of 30 to 60 seconds of which the child has to be looking at one specific point for approximately one second at a time. Ideally, measurements are being performed in 9 different directions of gaze. The DAISY has to be able to register exactly where the child is looking at. Also of importance is that the eye-catcher needs to be attractive to the child and can’t disturb the DAISY’s functioning, or the other way around. These basic thoughts and considerations formed the basis for my research. Automatic measuring and entertaining The final result will be that both the actual measurement as drawing the attention of the child, can be done automatically in stead of manually using the combination of the DAISY and eye-catcher. Process of the project The final design of the eye-catcher was designed after an in depth process of research of the human eye, spending time with different orthoptists and eye doctors, watching strabismus surgery, in depth study of the development of the DAISY, performing a survey among hundred orthoptists (one third of all orthoptists in The Netherlands), further development of ideas in a creative session and literature research on children in the relevant age group. The design that was made was then tested on the target group. Design of the eye-catcher The essence of the design consists of popular children’s comic book figures that are digitally shown, one after the other, in nine different directions of gaze. Results practical tests with the eye-catcher The main objective of testing was to establish whether the eye-catcher was able to draw the children’s attention. Results showed that the eye-catcher was definitely capable of doing so, as well as directing the children’s attention towards one of the nine directions of gaze and keep their focus there. The nine different directions were not always easy to distinguish. Eye versus head movements towards a stimulus The test results confirmed what is described in the current literature on this matter: a child first draws his eyes towards a certain direction, for example towards the left. Secondly, he will turn his entire head to the left so that he does still look at the same object but his eyes are not turned leftwards anymore.