TABLE 1.
Overview of the different studies included in the analysis and their light exposure (LE) general characteristics
| Author(s) (year) | # Data points a | Light source | Narrow band | Light characteristics (CCT in K or peak wavelength in nm) | Pupil dilation | Start LE | LE duration(s) (min) |
|---|---|---|---|---|---|---|---|
|
Bojkowski et al., 1987 b [19] |
1 | Fluorescent | No | 5500 K | No | 00:30 | 30 |
|
Bojkowski et al., 1987 b [19] |
1 | Fluorescent | No | 5500 K | No | 01:30 | 30 |
|
Brainard et al., 1988 c [20] |
5 | tungsten, monochromatic filter | Yes | 509 nm | Yes | 02:00 | 60 |
|
Wright et al., 2000 d [21] |
3 | Fluorescent | No | 4000 K | No | 20:00 | 120, 180, 240 |
|
Zeitzer et al., 2000 e [22] |
21 | Fluorescent | No | 4000 K | No | 23:00 | 195 |
|
Brainard et al., 2001 b [9] |
68 | Xenon arc lamp & monochromator | Yes | 440, 460, 480, 505, 530, 555, 575, 600 | Yes | 02:00 | 90 |
|
Thapan et al., 2001 b [10] |
35 | Metal halide arc & monochromatic filter | Yes | 424, 456, 472, 496, 520, 548 | Yes | 23:30 | 30 |
|
Whitmore et al., 2001 b [23] |
2 | Fluorescent | No | 3500 K | No | 02:00 | 60 |
|
Whitmore et al., 2001 b [23] |
2 | Fluorescent + green filter | Yes | 530 | No | 02:00 | 60 |
|
Wright & Lack, 2001 b [24] |
8 | LED | Yes | 470, 497, 525, 595, 660 | No | 00:00 | 120 |
|
Wright & Czeisler, 2002 b [25] |
1 | LED | Yes | 497 | No | 00:00 | 120 |
|
Wright & Czeisler, 2002 b [25] |
1 | White LED | No | 4000 K | No | 00:00 | 120 |
|
Wright & Czeisler, 2002 b [25] |
1 | Fluorescent | No | 4000 K | No | 00:00 | 120 |
|
Gronfier et al., 2004 e [26] |
1 | Fluorescent | No | 4100 K | No | 1,1 h before habitual bedtime | 195 |
|
Wirz‐Justice et al., 2004 d [27] |
5 | Fluorescent | No | 4700 K | No | 21:00 | 30, 60, 90, 120, 180 |
|
Cajochen et al., 2005 d [6] |
6 | Xenon arc + interference filter | Yes | 460, 550 | No | 21:30 | 30, 60, 120 |
|
Herljevic et al., 2005 b [28] |
7 | Metal halide + monochromatic filter | Yes | 456, 548 | Yes | 23:30 | 30 |
|
Hanifin et al., 2006 b [29] |
3 | Xenon arc + monochromator | Yes | 460, 630, 700 | Yes | 02:00 | 90 |
|
Revell & Skene, 2007 b [30] |
3 | Ultra‐high‐pressure mercury | No | ~6600 K | Yes | 00:30 | 30 |
|
Revell & Skene, 2007 b [30] |
3 | Ultra‐high‐pressure mercury + interference filter | Yes | 479 | Yes | 00:30 | 30 |
| Brainard et al., 2008
b
[31] |
10 | LED | Yes | 420 nm, 460 nm | Yes | 02:00 | 90 |
|
Kozaki et al., 2008 d [32] |
3 | Fluorescent | No | 2300 K, 3000 K, 5000 K | No | 01:00 | 90 |
|
Gooley et al., 2010 e [8] |
8 | Xenon arc & monochromator | Yes | 460, 555 | Yes | 23:00 | 48.75, 146.25, 243.75, 341.25 f |
|
Revell et al., 2010 d [33] |
2 | Fluorescent | No | 4000 K, 17 000 K | Yes | 23:00 | 30 |
|
Revell et al., 2010 c [33] |
6 | Ultra‐high‐pressure mercury + interference filter | Yes | 437, 479, 532, 479 + 532, 437 + 470 | Yes | 23:00 | 30 |
|
Santhi et al., 2012 d [34] |
12 | Fluorescent yellow (TL16) | No | Yellow/blue‐depleted | No | 19:35 | 30, 60, 90, 120, 180, 240 |
|
Santhi et al., 2012 d [34] |
6 | Fluorescent (TLD 827) | No | 2700 K | No | 19:35 | 30, 60, 90, 120, 180, 240 |
|
Santhi et al., 2012 d [34] |
6 | Fluorescent (17000K) | No | 17 000 K | No | 19:35 | 30, 60, 90, 120, 180, 240 |
|
West et al., 2011 b [35] |
8 | LED | Yes | 469 | No | 02:00 | 90 |
|
West et al., 2011 b [35] |
1 | Fluorescent | No | 4000 K | No | 02:00 | 90 |
|
Chang et al., 2012 e [36] |
1 | Fluorescent | No | 4100 K | No | 0:30 | 120 |
|
Brainard et al., 2015 b [37] |
18 | Fluorescent | No | 4000 K, 17 000 K | No | 02:00 | 90 |
|
Gabel et al., 2017 d [38] |
2 | Fluorescent | No | 2800 K, 9000 K | No | 22:00 g | 180 |
|
Nowozin et al., 2017 b [18] |
18 | Fluorescent, white LED, halogen, high‐pressure sodium, Xe‐filled fluorescent, metal halide | No | 1500 K, 12 000 K | No | 22:00 | 30 |
|
Souman et al., 2018 d [5] |
5 | White LED (CRI 57) | No | 2609 K | No | 21:00 | 30, 60, 90, 120, 180 |
|
Souman et al., 2018 d [5] |
5 | White LED (CRI −22) | No | 2641 K | No | 21:00 | 30, 60, 90, 120, 180 |
|
Hanifin et al., 2019 e [39] |
2 | Fluorescent | No | 4000 K, 17 000 K | No | 22:45 | 195 |
|
Nagare et al., 2019 b [40] |
2 | White LED | No | 3000 K | No | 00:00 | 60 |
|
Nagare et al., 2019 b [40] |
2 | ‘cyan‐gap’ modified LED | No | cyan‐gap | No | 00:00 | 60 |
|
Nagare et al., 2019 b [40] |
32 | White LED | No | 2700 K, 6500 K | No | 23:00 | 30, 60, 120, 180 |
Number of data points that were extracted from the group mean melatonin (suppression) values as reported within a particular study for different light exposure durations and spectral compositions.
Study with dim light condition in which melatonin levels were >10 pg/ml at start time of light exposure. Light‐induced melatonin suppression corrected for the % change in melatonin in the dim light condition (see point 3 in the Section 2.2).
Study reporting % melatonin suppression relative to the values before lights on (see point 5 in Section 2.2).
Study reporting melatonin data as a function of time for both a dim light condition and the test light condition (see point 2 in Section 2.2).
Study reporting % suppression based on area under the curve (see point 4 in Section 2.2).
In Figure 2 the exposure duration points from this study were mapped to the closest light exposure bin: for instance the durations 48.75, 146.25, 243.75 and 341.25 min were mapped into the Figure 2 bins of 60, 180, ≥240 and ≥240 min, respectively.
When the light exposure started before the time point of the dim light melatonin onset (DLMO), it is assumed that the light exposure has only started at the DLMO, see Section 2.2.