Should you use a night light in your child's room?

Are you worried that your baby or toddler might be afraid of the dark? Many parents think that introducing a night light will help ease their child's anxiety and reduce or eliminate night waking. Although there are some situations where introducing a night light may be a good choice, light has a direct biological effect on your child's circadian rhythm. Putting a light into your child's sleep environment could backfire and make sleep problems worse. This blog will help you decide whether introducing a night light into your child's room is right for your situation.

The Science

Light is a signal to the brain to wake up

There are two sleep drives, the homeostatic drive (aka sleep pressure) and the circadian rhythm. You can read more about how these sleep drives work and interact in this blog. The circadian rhythm is your internal clock. Everyone's circadian rhythm is a little longer or shorter than 24 hours. In order to stay aligned with the 24-hour day and to keep sleep at night and waking during the day, our body's circadian rhythms use the light that we see to reset our internal clock every day. A simple way to think about this is that our bodies are always looking for light to signal the timing of daytime waking. When your body is exposed to light at night, your body can misinterpret that light as a daytime cue and can start to promote waking at night.

Although the light emitted from a nightlight is much dimmer than sunlight, recent studies have demonstrated that young children are much more sensitive to low levels of light exposure compared to adults. In fact, one study found that light levels as low as 5 lux (the equivalent of five candles burning one foot away) was enough to affect the circadian system. In addition, the wavelength, timing, and duration of light exposure all matter. Blue light has a stronger impact on the circadian rhythm and typical white nightlights often contain a lot of blue light. Light has a stronger impact when it is preceded by darkness, which means that when your child is asleep and then wakes up, light will have a greater impact. Finally, most studies show that the longer one is exposed to light, the bigger the effect of the light. Altogether, this means that you shouldn't introduce a night light unless you need it to safely move around the room or unless you are sure that your child has anxiety about being in the dark.

Fear of the dark is understudied and complicated

Some children do have a legitimate fear of the dark. There isn't enough research on how fear of the dark develops in babies and toddlers, but studies have suggested that it arises from learning (i.e., hearing that darkness is scary from peers or adults), the inability to see in very dim light, or innate survival mechanisms. It is important to avoid planting fear of the dark in your child's mind. For example, don't say "are you afraid of the dark?" because that statement could trigger concern about being in the dark. If you suspect that your child has a visual impairment at night (night blindness), then it may be helpful to have your child evaluated by an ophthalmologist. The little research that exists suggests that introducing a light into the sleep environment can be helpful for some children, but has also shown that light can also cast shadows that can lead to new anxieties. The bottom line here is that adding a night light to your child's room isn't likely a quick fix even if your child does fear the dark.

How do you know if your child has a legitimate fear of the dark?

It can be hard to determine whether a child has a legitimate fear of the dark. Sometimes a toddler will use the word 'scared' because parents will often respond to that word differently than other words. Put differently, your child might have learned the word scared yields attention from you, without actually understanding what the word means. It's also possible that your child knows what the word scared means, but also knows that you respond to it differently than other words. The key is to listen to your child's affect to determine whether the words your child is using reflect the emotion. If your child is obviously distressed, then fear of the dark may be the issue; however, if your child is fine going to sleep in a dark room but distressed after night waking, then the issue may actually be nightmares or night terrors (this blog discusses more about toddler fears and anxieties). On the other hand, if your child wakes up and says "scared" without any emotion, then that might mean that your child has learned to use that word to gain attention from you.

If you suspect that your child is really afraid of the dark, then consider helping your child cope by spending time together in the dark. For example, give your child plenty of time to transition to the darkness with you close by. You might turn out the lights and tell your child a story, listen to music together, or read a book with a flashlight to make the darkness less stressful. If your child's distress is intense, then you may want to discuss your concerns with your pediatrician who can help you determine whether a psychologist referral would be appropriate.

When should you use a night light?

Consider using a night light only if:

1. You need to be able to see in your child's room to attend to your child without tripping during night feeds and diaper changes.

2. Your child has a legitimate fear of the dark that cannot be mitigated in other ways.

What type of night light should you choose?

If you think a night light would help your child (or if you need one for safety), then make sure it has the following characteristics:

1. Dim. Choose the dimmest possible option. A bright nightlight will have a stronger impact on your child's circadian rhythm and will also cast stronger shadows around your child's room. Your child's eyes will adjust to a dim night light, so a bright one isn't that helpful anyway.

2. Red. Red may not seem like an obvious choice for a nightlight, but red light has the smallest effect on the circadian rhythm (although it does still have an effect!). Stay away from blue, green, or white night lights because these will have a stronger impact on your child's circadian rhythm.

3. Distant. Place the night light as far from your child's bed as possible.

But wait! My child already has a bright night light and I think it might be a problem!

It's not a great idea to take away a night light if your child is used to having one on all night. Having a night light on all night in your child's sleep environment and then turning it off could trigger a fear of the dark. If your child currently has a night light that doesn't meet these criteria, then consider swapping it out for one that is dim, red, and distant as noted above. If you are concerned that your toddler might react negatively to having a new night light, then let your child choose a new night light. Pick 2-3 options that your child might like (e.g., a red car, red star, favorite red cartoon character etc.) that meet the criteria and swap out the old night light for the new one.

Problems are usually more complicated than just a change in sleep environment

Although it's important to make sure your child feels safe and comfortable for sleep, changes to your child's sleep environment alone probably won't result in meaningful change. If you need more help, then check out our other blogs on topics like night weaning, napping, and sleep regressions. If you have a baby between 6-15 months old, then check out our self-paced sleep training class. If you need personalized support, then feel free to schedule a consultation with us so that we can help you to develop a plan to improve your baby or toddler's sleep issues.

References

Jenni, O.G. and LeBourgeois, M.K., 2006. Understanding sleep–wake behavior and sleep disorders in children: the value of a model. Current opinion in psychiatry, 19(3), p.282.

LeBourgeois, M.K., Wright Jr, K.P., LeBourgeois, H.B. and Jenni, O.G., 2013. Dissonance between parent‐selected bedtimes and young children's circadian physiology influences nighttime settling difficulties. Mind, Brain, and Education, 7(4), pp.234-242.

Higuchi, S., Nagafuchi, Y., Lee, S.I. and Harada, T., 2014. Influence of light at night on melatonin suppression in children. The Journal of Clinical Endocrinology & Metabolism, 99(9), pp.3298-3303.

Sidiki SS, Hamilton R, Dutton GN. Fear of the dark in children: is stationary night blindness the cause? BMJ. 2003 Jan 25;326(7382):211-2. doi: 10.1136/bmj.326.7382.211. PMID: 12543840; PMCID: PMC1125066.

Muris, P., Merckelbach, H., Ollendick, T.H., King, N.J. and Bogie, N., 2001. Children's nighttime fears: Parent–child ratings of frequency, content, origins, coping behaviors and severity. Behaviour research and therapy, 39(1), pp.13-28.

Kushnir J, Sadeh A. Sleep of preschool children with night-time fears. Sleep medicine. 2011 Oct 1;12(9):870-4.