Prospective quantification of near work using the experience sampling method

Introduction. The assessment of individuals' near work by survey methods is challenging. The feasibility of the Experience Sampling Method to quantify daily visual tasks was evaluated. Methods. Twenty-one subjects were random ly paged five times per day for 6 days. When paged, the subjects dialed int o a telephone survey to report the nature, duration, and working distance o f their visual activity at the time of the page. Results. The overall respo nse rate was 81.3% (512/630 pages). The individual response rates varied fr om 6.7% to 100% (median, 86.7%). Responses were grouped into 11 categories/ activities for ease of analysis. Of 506 responses, the most common activity category was "distance tasks," which included driving and walking (N = 92) . Other common responses included computer use (N = 68), reading (N = 66), household tasks, e.g., cleaning, cooking, and showering (N = 64), and watch ing television (N = 61). Activities with a mean distance less than or equal to 26 inches (arm length) were combined as near-work responses and account ed for 54.3% (258/475) of all responses. Conclusion. A modification of the Experience Sampling Method can be used to obtain a "real-time" sampling of visual activities.