Corneal illuminance (lux) CLA CS Mean pupil diameter(mm) Mean suppression (%) 95% confidence interval (%) Sample size for a < 0.05 and b < 0.05 (n)
8 6 0.01 6.8 -5.8 -24.5 – 12.8 386*
22 16 0.02 6.9 -13 -38.4 – 12.5 154*
60 (study 1) 42 0.06 6.4 4.8 -10.2 – 19.9 405
60 (study 2) 42 0.06 6.0 -10 -34.3 – 13.9 205*
200 141 0.19 4.6 19 6.7 – 30.7 17
720 509 0.42 3.9 37 23.0 – 50.5 8
*Sample size need to reach statistically significant negative suppression levels.
Table 2: Corneal (photopic) illuminance levels (lux) employed in the two studies together with the associated levels of Circadian Light (CLA) and Circadian Stimulus (CS) from one-hour exposure, the measured mean pupil diameters, the measured mean levels of nocturnal melatonin suppression, the 95% confidence intervals for the mean melatonin suppressions, and the sample sizes needed to meet a criterion probability of 0.05 for both Type I (α) and Type II (β) errors.