Figure 4: Box plot for changes in the Perceived Stress Scale score from 6 to 12 months according to subjects who did or did not develop a loss of confidence in their vision self-monitoring between 6 to 12 months. The bottom and top of the box are the 25th and 75th percentile (lower and upper quartiles, respectively), and the band near the middle of the box is the 50th percentile (the median). Outliers by more than 1.5 times the interquartile range are indicated by dots.