Is it good to sleep with the light on?

February 03, 2025

Many people leave a bedside lamp on at night, whether out of habit, for comfort, or to reassure children. But is this practice truly beneficial? What are its effects on sleep quality and health? Let's explore the answers together.

The impact of light on our sleep cycle

The role of melatonin

Our bodies follow a circadian rhythm , a biological clock influenced by light. When light levels decrease, our brains produce melatonin , a hormone that promotes sleep. Sleeping with the lights on can disrupt this production, resulting in poorer sleep quality.

Prolonged exposure to artificial light can disrupt the body's biological clock, delaying sleep onset and reducing the duration of deep sleep. This can have long-term repercussions on concentration, mood, and even physical health.

The effects on deep sleep

Sleep is divided into several phases, including deep sleep, which is essential for physical and mental recovery. Prolonged exposure to artificial light can reduce the time spent in this phase, causing a feeling of fatigue upon waking.

Artificial light, particularly the blue light emitted by screens, interferes with sleep quality by prolonging light sleep and reducing the duration of REM sleep. This can lead to more frequent awakenings during the night and less restorative sleep.

Differences depending on the type of light

Not all lights are created equal. Blue light, emitted by screens and some LED bulbs, is particularly harmful because it inhibits melatonin production. In contrast, soft, warm light has a less disruptive impact on sleep.

Studies show that red light is the least disruptive to sleep, while cool white light has a stimulating effect similar to daylight. Therefore, it is recommended to choose low-intensity, warm-toned bulbs to minimize negative effects.

Some lamps influence sleep: choose your light therapy lamp carefully .

The health risks of sleeping with the light on

An increased risk of metabolic disorders

Studies have shown that sleeping in a bright environment may be associated with a higher risk of obesity and diabetes. Disrupted sleep interferes with insulin regulation and promotes weight gain.

Disrupted sleep also leads to hormonal changes that increase appetite and reduce feelings of fullness. This can result in excessive calorie consumption and promote weight gain.

Effects on mental health

Disrupted sleep can impact mental health, increasing stress, anxiety, and even the risk of depression. A dark environment is therefore recommended to promote optimal well-being.

Sleep deprivation or poor sleep quality affects emotional regulation and stress management. People exposed to light during the night tend to be more irritable and less resilient to daily challenges.

Impact on blood pressure

Light at night can also influence blood pressure . One study found that nighttime exposure to light could disrupt the cardiovascular system and increase the risk of heart disease.

Insufficient or poor quality sleep can also contribute to hypertension and chronic inflammation, thus increasing the risk of long-term cardiovascular disease.

Situations where sleeping with a light on can be beneficial

For children and anxious people

Soft lighting, like a nightlight, can be reassuring for children or people prone to nighttime anxieties. In this case, it is advisable to use a dim, warm light .

Nightlights can help establish a sleep routine in children and reduce their fear of the dark without excessively disrupting their sleep.

For elderly people

For older people, leaving a light on can prevent falls when waking up during the night. A bedside lamp equipped with a motion sensor can be a good alternative.

Sleep disorders are common among the elderly, and appropriate lighting can help them better manage their nighttime awakenings.

In the case of working irregular hours

Night shift workers often have to sleep during the day, which can disrupt their biological clock. In these cases, appropriate lighting can help regulate their sleep.

People with atypical schedules are advised to use blackout curtains to sleep in the dark and to avoid any exposure to blue light before bedtime.

Tips for optimal sleep

Avoid blue light before sleeping (smartphones, tablets, TV).
Opt for dim lighting if necessary.
Use blackout curtains to block out external light sources.
Establish a regular bedtime routine to promote quality sleep.
Opt for warm light bulbs with low intensity for bedrooms.

Conclusion

While sleeping with the light on may be comforting for some, a dark environment is preferable for improving sleep quality and preserving health. Scientific research has demonstrated the negative impact of nighttime light on melatonin production, metabolic health, and blood pressure. For suitable lighting, explore our collection of bedside lamps and find the perfect light for your nights.