| The two most common suggestions for the etiology of myopia are the genetic and the use-abuse hypotheses. To evaluate a use-abuse mechanism for the etiology of myopia, quantification of daily visual activities must be achieved. Although surveys, interviews and questionnaires have been used to answer this question, compliance and dependence on recall limit the use of these methods. A gold standard method for the quantification of near work does not currently exist. The purpose of this dissertation was to develop a method by which quantification of the nature, duration, and working distance of daily visual activities could be obtained in both adults and children.; The Experience Sampling Method was used to record visual activities of 63 optometry students and 31 children. Each subject was paged randomly throughout each testing period. Once paged, each subject completed a telephone voicemail survey and reported the nature, duration, working distance and visual correction worn during the visual task performed at the time of the page. The data were then transcribed into a log and categorized by type of activity.; The proportion of time spent doing near work (reading, writing, studying, computer use, or near hobbies) was 30.8% for adults and 25.0% for children 8 years of age and older. Eighteen subjects completed the testing on two occasions, six months apart, with different near work demands. A comparison of the percentage of near work between the first and second testing periods produced a significant difference in the amount of near work observed (mean difference = 13%, paired t-test, p = 0.001).; A comparison of data obtained using the Experience Sampling Method and that reported on a questionnaire showed agreement between methods for the proportion of time spent on computer use and household tasks (paired t-tests, p = 0.231 and 0.074, respectively). Significant differences in the proportion of time spent doing near hobbies, playing video games and watching television, doing distance activities, and in conversation were found between the two methods (paired t-tests, p = 0.007, 0.003, 0.0001, and 0.0001, respectively).; In conclusion, the Experience Sampling Method is an acceptable method for the quantification of near work in both adults and children. |
