Sleep is an important factor to promote the wellbeing and recovery of patients. Impaired sleep is a known hospital stressor, and hospitalized patients struggle to get sufficient sleep at night due to factors like discomfort, worries, noise, inappropriate light exposure and pain.

In many healthcare facilities access to daylight is limited. One study investigating lighting levels in acute care medical patients, found that patients were dwelling in low levels of light daytime¹ and patient’s 24-hour light/dark cycle has been found to be extremely weak and phase delayed relative to the solar cycle². No seasonal difference in light intensity of patient rooms was found in one study, indicating only low levels of daylight exposure.

Current standards and guidelines for lighting systems within normal patient rooms specify horizontal illuminance thresholds in the range of 100–300 lux³, a level insufficient to generate the same benefits as the outdoor illuminance (2000–100 000 lux) under which we have evolved. Not surprisingly, circadian dysrhythmias are often found⁴ and hospitalized patients often suffer from sleep and circadian rhythm disruption⁵.

BCL guide

Improve shift work

Many shift workers experience symptoms of sleep such as excessive sleepiness or insomnia and two thirds of medical events are contributed to the third shift. Studies have shown that exposure to high levels of bright light at night increases alertness but this has to be balanced with the effect that light has on suppression of melatonin. The need of lighting in between tasks, for example “light showers”, might be appropriate to retain the circadian rhythm.

Shorten length of stay

Daytime exposure to high illuminances, from either sunlight or a few hours of bright-light therapy, is known to have beneficial effects on clinical parameters such as recovery, length of stay (LOS), depression, anxiety and use of pain medication. In a study investigating the hospital environment, inpatients had over three days shorter stay when admitted to rooms facing east compared to those in rooms facing west¹⁰.

Benefit neonatal care

Keeping preterm patients in a continuously dark or continuously lit environment while in the NICU, deprives them of the circadian stimuli they would have received during gestation. In a systematic review by the Cochrane Collaboration the authors suggested better outcomes regarding growth and length of stay with cycled light than with continuous near darkness or bright light¹⁷.

In care facilities, it is usual for people to spend the majority of time indoors. The need for light increases with age as the pupil gets smaller and the lens thickens absorbing more light.


1. Bernhofer EI, Higgins PA, Daly BJ, Burant CJ, Hor- nick TR. Hospital lighting and its association with sleep, mood and pain in medical inpatients. J Adv Nurs. 2014;70(5):1164-1173. doi:10.1111/jan.12282
2. Danielson SJ, Rappaport CA, Loher MK, Gehlbach BK. Looking for light in the din: An examination of the circadian-disrupting properties of a medical intensi- ve care unit. Intensive Crit Care Nurs. 2018;46:57-63. doi:10.1016/j.iccn.2017.12.006
3. CEN IES. 2011.
4. Billings ME. Circadian DysrhythmiasintheIntensive Care Unit. 2019;31(2015):393-402.
5. Tan X, van Egmond L, Partinen M, Lange T, Benedict C. A narrative review of interventions for improving sleep and reducing circadian disruption in medical inpatients. Sleep Med. 2019;59:42-50. doi:10.1016/j.sleep.2018.08.007
10. Taguchi T, Yano M, Kido Y. Influence of bright light therapy on postoperative patients: A pilot stu- dy. Intensive Crit Care Nurs. 2007;23(5):289-297. doi:10.1016/j.iccn.2007.04.004
17. Morag I, Ohlsson A. Cycled light in the intensi- ve care unit for preterm and low birth weight in- fants. Cochrane Database Syst Rev. 2016;2016(8). doi:10.1002/14651858.CD006982.pub4