Light Therapy for Shift Workers

Shift Workers: Re-Timer, promoting safety in the workplace


Shift work is designed to make use of all 24 hours of the clock each day of the week, including both long-term night shifts and work schedules in which employees change or rotate shifts. People who do shift work or who have irregular work hours are often working when their bodies are telling them to sleep. They often do not follow any regular sleep or wake pattern, which can be very disruptive on a daily basis. 

How can shiftwork affect my sleep?


Generally, the body is programmed to sleep best overnight and to be most alert during the day and early evening. If you work night shift, it might not be easy to sleep enough or to sleep well during the day. If you start work very early in the morning, it might be hard to sleep in the evening. The average shiftworker sleeps one hour a day less than someone who doesn't work shifts. Some shiftworkers sleep up to four hours a day less than normal, but this is not common.

Up to 16% of the population are shift workers. Studies report that 30% of these workers suffer from daytime sleepiness. For companies operating in logistics and heavy industries, worker fatigue can result in workplace accidents and lost productivity.

Shift work is considered a risk factor for many health problems. It has many negative cognitive effects (e.g., learning and memory deficits, loss of attention and vigilance). In addition, rotating night shift work disrupts our circadian clocks which is associated with a higher probability of developing obesity, diabetes and cardiovascular disease. (1,2)


How does light therapy help me with shiftwork? 

Professor Lack says, “Light can help a shift worker re-time their body clock, so they feel awake and alert whilst on the job. Furthermore, we know light has a waking effect on the body, so using light before a shift can assist you alertness levels” 

What is important is knowing when to administer light therapy based on your shift. As a general rule, using the Re-Timer 30 - 50 minutes before your shift will help you feel more energetic.  

Example 1:

A nurse starting work at 11pm working until 7 am for 4 days and then switches to 7am until 3pm for 10 days. 


Example 2: 

Always starts his shifts at 5:30 am

At 530 am Mark arrives at work and the sun is not up. To help him feel more awake and alert he uses a light device for 50 minutes to start his day. The soft glow and portability of the device allows him to respond to emails he receives overnight whilst using the Re-Timer.


  1. ^ Delezie J, Challet E (2011). "Interactions between metabolism and circadian clocks: reciprocal disturbances."Ann N Y Acad Sci 1243: 30–46. doi:10.1111/j.1749-6632.2011.06246.xPMID 22211891.
  2. ^ Scheer FA, Hilton MF, Mantzoros CS, Shea SA (2009). "Adverse metabolic and cardiovascular consequences of circadian misalignment."Proc Natl Acad Sci U S A 106 (11): 4453–8. doi:10.1073/pnas.0808180106PMC 2657421PMID 19255424.