Fig. 4

Subject tear sampling questionnaire responses. A Anxiety pre-sampling, B Anxiety post-sampling, C Discomfort during sampling, D Difficulty of sampling, E Willingness to repeat the sampling method if it could provide useful health information, F Overall experience, G Rank order of preferred tear sampling method. All questionnaires were graded on a scale of 0 = none, to 10 = extreme, except for a willingness to repeat (graded “yes,” “no,” or “unsure”) and overall experience (graded 0 = terrible, to 10 = excellent). Error bars represent standard deviation, n = 6. * = p-value ≤ 0.05, ** = p-value ≤ 0.01