Purpose: To quantify the central attention-diverting effect of hands-free cellular phone conversation on visual field awareness.
Design: Experimental study.
Methods: Twenty male and 21 female healthy participants performed a pretest and baseline Esterman visual field examinations with the Humphrey Systems Visual Field Analyzer II. During the consequent third examination, each participant engaged in a hands-free conversation using a cellular phone. The conversation was the same for all participants. Visual field performance parameters were compared between the second (baseline) examination, and the third (test) examination for each eye.
Results: During phone conversation, missed points increased from mean 1.0 +/- 1.5 to 2.6 +/- 3.4 (P < or =.001) in the right eye and from 1.1 +/- 1.53 to 3.0 +/- 3.4 (P <.001) in the left eye. Fixation loss increased from mean 7.8% to 27.4% (P <.0001) and from 7.2% to 34.8% (P <.0001) for the right and left eyes, respectively. Test duration increased by a mean of 0.28 seconds (15%) per stimulus (P <.0001). Approximately half of missed points were inside the central 30 degrees. There was no significant difference in the performance of male and female participants.
Conclusion: We describe a new model for the quantification of the attention-diverting effect of cellular-phone conversation on the visual field. In the current study, cellular hands-free conversation caused some subjects to miss significantly more points, react slower to each stimulus, and perform with reduced precision. Legislative restrictions on concomitant cellular-phone conversation and driving may need to be based on individual performance rather than a general ban on cellular phone usage.