• June 20, 2025 1:15 am

How blue light from screens affects sleep quality

Learn how blue light from screens affects sleep, focus, and cognitive abilities, and how to reduce its harmful effects.Learn how blue light from screens affects sleep, focus, and cognitive abilities, and how to reduce its harmful effects.

In today’s world of digital technologies, screens are part of our daily lives — from smartphones and laptops to televisions and e-readers. At the same time, more and more studies suggest that blue spectrum light emitted from screens can negatively affect our bodies. Sleep and cognitive functions, including memory, attention, and thinking speed, suffer the most. Why this happens, what health consequences screen overuse brings, and how to protect yourself — Baltimore Chronicle explores further.

What is blue light and why is it everywhere?

Blue light is a short-wavelength part of the visible light spectrum with high energy. It exists in natural sunlight, but a significant portion also comes from artificial sources: smartphone, tablet, and computer screens, LED TVs, and LED lighting.

Blue light plays an important role in maintaining our biological rhythm: it helps us stay alert during the day. However, at night, an excess of this spectrum can disrupt the natural daily cycle.

Especially problematic is blue light at night, as it affects melatonin production — the sleep hormone. This leads to reduced sleep quality, increased fatigue, and problems with focus the following day.

Common sources of blue light in daily life:

  • Smartphones and tablets
  • Computers and laptops
  • LED TVs
  • LED lighting
  • E-readers with backlighting

The impact of blue light on sleep quality

Sleep quality depends on the synchronization of our biological clock with natural light and dark cycles. Blue light entering the eyes in the evening disrupts this rhythm, causing sleep disturbances.

When we use gadgets before bed, the body receives a signal that it’s still daytime. As a result, the brain delays melatonin production, which leads to difficulties falling asleep. Sleep becomes more superficial and shorter.

The accumulation of such disruptions leads to chronic fatigue, lowered immunity, irritability, and problems with emotional regulation.

Signs of sleep disturbances caused by screens:

  • Difficulty falling asleep
  • Frequent nighttime awakenings
  • Feeling tired in the morning
  • Insomnia or light, unrestful sleep
  • Shortened deep sleep phase

How blue light affects cognitive functions

Cognitive functions are the brain’s ability to memorize, process information, concentrate, and make decisions. Sleep disturbances caused by blue light directly affect these processes.

Chronic lack of quality sleep leads to reduced concentration, memory impairment, slower reaction times, and less effective mental performance. In children, this can cause learning difficulties, and in adults — reduced professional productivity.

The most common cognitive effects of blue light exposure:

  1. Decreased short-term memory
  2. Weakened concentration ability
  3. Impaired logical thinking
  4. Slower reaction times
  5. Increased emotional instability

Comparison of cognitive performance based on screen use before sleep

Screen use duration before sleepSleep qualityMemoryConcentrationMood
Less than 30 minutesHighGoodHighStable
30–60 minutesModerateAverageModerateFluctuating
More than 60 minutesLowPoorLowIrritable

Who is most affected by blue light?

Studies show that children, teenagers, and older adults are most vulnerable to blue light exposure. Children’s biological rhythm systems are not yet fully developed, while older adults naturally produce less melatonin.

Also at risk are office workers, freelancers, and anyone who spends more than 6 hours a day in front of screens.

How to reduce the negative effects of blue light

Although it’s impossible to completely avoid blue light in the modern world, there are effective ways to minimize its impact.

Practical tips:

  • Use night mode or blue light reduction mode on devices
  • Avoid screen use at least one hour before bedtime
  • Use dim, warm lighting in the evening
  • Wear blue light blocking glasses
  • Choose non-backlit e-readers or read printed books
  • Maintain a consistent sleep schedule, going to bed at the same time every night

What are some screen-free alternatives for evening relaxation?

To reduce gadget use before bed, it’s worth incorporating alternative evening activities. These not only lower blue light exposure but also positively affect mental well-being.

Recommended evening activities:

  • Reading paper books
  • Meditation or breathing exercises
  • Playing board games with family
  • Journaling or writing
  • Listening to soft music or audiobooks

Why it’s worth limiting blue light exposure

Blue light is not an enemy if used wisely. The problem lies in excessive and uncontrolled exposure, especially in the evening. Sleep and cognitive disruptions are just the tip of the iceberg when it comes to the consequences of prolonged blue light exposure.

To protect yourself, you only need to adopt a few simple habits. These will help preserve mental clarity, improve sleep, and support emotional balance — even in the digital age.

Earlier we wrote about how to improve eyesight at home.

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