The lights in your home and at the office can make a difference to the way you feel and can even affect your health.
In fact, according to new research published in the Journal of Clinical Endocrinology & Metabolism, exposure to certain types of electric light before bed and at night can increase the risk of type 2 diabetes, high blood pressure and cancer.
So why is light so important, and how can you get the right amount of it?
Why is light important?
Our bodies need a good quantity of light at the right intensity and at the right time of day to act as cues for our internal body clock.
Light in the morning helps us wake up and feel alert and energised, while dimmer light at night cues us to go to sleep and stay asleep.
‘Light is critical for our health and wellbeing. Ensuring that we receive adequate light levels at the appropriate time of day benefits our alertness, mood, productivity, sleep patterns and many aspects of our physiology,’ says Dr Victoria Revell, a chronobiologist at the University of Surrey.
So, how much light do we need?
The amount of light we need depends on the time of day and the activities we are trying to accomplish.
During the day, we need high levels of light to stay alert for school or work, while in the evening and night we want to start feeling more relaxed and ready for bed.
‘To ensure your body is getting enough light during the day, it’s important to spend an hour or more outdoors’, advises Sue Pavlovich from the Seasonal Affective Disorder Association (SADA).
‘Getting outside for a walk in your lunch hour, even in the winter sun, will be good for you. This is because surrounding light, which is outside light that envelops you, is always better than artificial light because it’s stronger and brighter.’
In fact, sunlight is between 50,000 and 100,000 lux (the measurement unit of light), compared to a normal light bulb (250 to 500 lux) or even a light box, which reaches 10,000 lux.
However, for sleeping, lights should start to be dimmed and TV’s switched off an hour before bed because our bodies are hardwired to wake up or stay awake when light is bright and to feel sleepy when it starts to get darker and darker.
If you stay in bright light before bed, you’re telling your body it’s time to perk up and be alert.
Too much artificial light
The problem with using artificial lights at night time is they decrease levels of melatonin – a hormone, which is produced by the pineal gland in the brain approximately between 9pm and 8am (depending on your regular sleep patterns).
This hormone is vital to our body’s health because it controls our ‘circadian rhythms’ also known as our daily body clock.
When the timing or intensity of melatonin is disrupted, physiological and mental functions are affected.
This can impact on:
- our ability to sleep well
- think clearly
- timing and release of hormones
- the regulation of blood pressure and glucose levels.
Do I need a light box for winter?
Getting enough outdoor daylight in winter is not easy, especially if you work long hours or shift patterns.
This is where light therapy can help. There are two types – light boxes and daylight simulation lights, which you use when you’re asleep.
These wake you up naturally with a gradual increase in light, which in turn prompts biological responses that make you feel more energetic and alert upon wakening.
This can help if you feel lethargic and suffer from the winter blues.
Light boxes are different says Pavlovich. ‘These help people with SAD (seasonal affective disorder) and are made to be used with your eyes open so light falls directly on the eye.
‘When using a light box, it’s important to use these as early as possible in the morning for the best effect and not late at night when they will disrupt your sleep and body clock.’
When and how often should I use light boxes?
‘Light therapy is a very individual thing,’ says Pavlovich.
‘It really depends on the reason you’re using it, which is why most people need to experiment to see what works.’
- If you work in a dimly lit office, it’s good to use a light box or lamp every working day to make up for the lack of natural light.
- If you feel lethargic and have trouble getting up in the mornings, daylight simulation lights can help.
- If you suffer with SAD, you’ll probably need to have a daily session in front of the light, maybe even twice a day during the darkest part of winter.
Are light boxes safe?
When purchased from a credible manufacturer, light boxes are safe.
‘However, people should always make sure they buy products that are certified as a medical device, otherwise you have no real guarantee that a light box has actually been designed for this specific purpose,’ says Jill Laughlin from Lumie, a producer of light boxes.
As for concerns that the light is bad for your eyes, Laughlin adds, ‘Properly designed light therapy products will incorporate special screens and filters that ensure UV levels are negligible and safe.’
Are there side-effects of using light boxes?
A few people do experience side-effects, but these are usually only mild including headaches, nausea and hyperactivity.
‘This can usually be solved simply by switching off the light and, over the next few days, gradually building up the time you spend in front of it to find a length of time that works best for you,’ says Laughlin.
‘Others complain of insomnia, but often this is down to using the light too close to bedtime.’