daytime functioning and night time sleep reduced alertness sleepiness
Conditions
Interventions
Each condition lasts 2 weeks: (1) normal office lighting (full spectrum light
vertical intensity ~ max 200 lux
(2) extra blue light during first 3 hours ..
(3) extra blue light during middle 3 hours ..
(4) extra blue light during last
3 hours of daytime working period.
Sponsors
Philips Consumer Lifestyle
Eligibility
Age
18 Years to 99 Years
Inclusion criteria
Inclusion criteria: • Healthy men and women, ages between 25 and 45 years • Indoor office workers with a 4-5 days working week • Habitual working days of 8-9h with at least 3 hours of computer work • In general the subjective energy profile over the day shows either a morning, a lunch, or an afternoon dip, characterized by increased sleepiness and lowered performance
Exclusion criteria
Exclusion criteria: • Psychiatric diagnose, e.g. mood disorder • Sleep disorder (PSQI>10, mild sleep complaints are allowed) • Alcohol or drug problems • Depressive mood (BDI-II NL > 8) • Regular use of photosensitizing medication, sleep medication or stimulant drugs • Colour blindness or other visual impairment that is not solved with contact lenses or glasses • On average more than 2 naps a week • High levels of caffeine intake during a day (> 8 cups) • Shift work schedule in the 3 months prior to participation • Travel over 2 or more time zones in 1 month prior to participation
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Subjective sleepiness and mood by rating scales. Rest-activity rhythms by activity meters and sleep characteristics with ZEO. | — |
Secondary
| Measure | Time frame |
|---|---|
| Evaluation of well being and subjective ratings of performance over two weeks, Eye strain and headache complaints. 24h- light intensity. Chronotype measurements with rating scale. | — |
Countries
Netherlands
Outcome results
None listed