What time of day should I limit blue light?

Did you know that the primary source of light is our sun? That means we are exposed to far more blue light in the day than at night. We have been constantly reminded of blue lights’ harms and potential hazards, but do we need to protect ourselves from the blue light every time?

The answer is NO! The blue light emitted from the sun at day time is beneficial. We don’t want to reach our offices, sleepy and tired, do we? We need blue light to make us alert during day time.

So, what should be the time of the day that we need to limit blue light? We will discuss it in this article.

What is the effect of blue light in the day time?

We, humans, are programmed to say active and alert during the evolution course in the daytime while retiring and off to bed at night. Blue light is the main factor in programming our sleep and wake cycle. How does blue light affect it?

Exposure of blue light reduces the sleep-inducing hormone in our body, called melatonin. Blue light also enhances our cognitive and boosts our mood so that we are active in performing our daytime functions.

What effect does blue light have at night?

At night our bodies are programmed to dose off. How? Lack of blue light causes melatonin expression on our bodies, and this melatonin will induce sleepiness. 

However, this is not the case in recent times. With modern-day digital devices and other illumination sources like fluorescent bulbs and LEDs, the exposure of blue light has increased way past the sunset.

This untimed blue light exposure has led to a decrease in melatonin production and hence more alertness at night.

What are the health impacts of blue light exposure at night?

Sleep is one of the necessities for optimal health. However, the sleep quality and quantity both are decreased in current times. The culprit? It is excessive exposure to blue light at night. There are many health impacts on this untimed blue light exposure.


Yes, insomnia is one of the primary sleep issues we are facing these days. The more the exposure of blue light at night, the less the expression of sleep-inducing hormone melatonin means less sleep and more alertness.

Tiredness at daytime 

Our body and brain need time to get recharged after a tiring day. We need to sleep to regain our mental and muscular strength back. However, with the lack of sleep, our bodies feel tired and mind fogged. Thus, we won’t be able to carry out our day time functions usually.

Eye strain and soreness

Ever felt tired and heavy eyes after prolonged use of computer screens or and smartphones. This is due to continuous blue light exposure on our eyes.

We are practically glued to our digital devices these days, and using our cellphones late till night is a routine of most of us. This excessive usage is costing us our eye health. Dry eyes and eye pain are all the digital eye strain symptoms caused due to excessive blue light exposure.

How can we limit the blue night at night time?

We can adopt some measures to decrease our blue light exposure at night and save ourselves from various health hazards.

Adjusting the brightness level at night 

We should adjust the brightness of our phones and other digital devices at night. Some apps are available that would reduce the harmful blue light emission.

Using blue light blocking glasses

Blue light blocking glasses have become an inevitable purchase these days. We can use these glasses while working on our digital devices or generally while we are out and about.  These blue light blocking glasses does not let an excessive amount of blue light exposure on our eyes hence helps us reduce the overall health impacts of blue light. 

Turning lights off one to two hours before bedtime

We need melatonin expression for sleep induction. LED lights and fluorescent bulbs emit blue light, which causes the suppression of melatonin expression.

It’s always a good idea to dim or turn off our lights before bedtime for a sound sleep.

Limiting screen time

Yes, the best measure is to limit the screen time altogether. We spend hours on our phones way past our bedtime without even realizing the potential damages.


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