What are the Effects of Blue Light (Especially on Your Eyes & Sleep)


Each of the lights present in the light spectrum has a different wavelength and energy. Rays present on the red end of the spectrum have lesser energy and longer wavelengths. Blue rays, on the other end, have more energy and shorter wavelengths.

The light that has a white hue can have a higher blue component. This can expose your eyes to higher wavelengths, emitted from the blue end of the light spectrum.

Blue Light and Its Effects

Blue light is similar to ultraviolet rays and has its benefits and dangers. This article looks are some important things about blue light:

1. Blue light is omnipresent

One of the primary sources of blue light is sunlight. We get exposed to the maximum amount of blue light by being outdoors during the daytime.

Besides sunlight, there are other indoor sources – mostly manmade - of blue light, including LED lighting, fluorescent lighting, as well as flat-screen televisions. Also, display screens of smartphones, electronic notebooks, computers, as well as various other digital devices, also emit blue light.

The amount of high-frequency, high-energy, or high-energy visible (HEV) light emitted by these devices is a fraction of what the sun emits. However, the time spent on and proximity to these devices can have a significant role in the development of problems related to the eyes.

Studies have shown that the eyes of a child will absorb more amount of blue light when compared to an adult, making them more susceptible to eye damages.

2. Eyes are not good at blocking blue light

Human eyes are designed to block certain lights and are unable to block other lights.

The adult human eye can block the harmful UV rays from reaching the sensitive retina. Less than 1% of the UV rays emitted by the sun reaches the retina (when not wearing protective eye gear).

The human eye, on the other hand, is not good enough to block blue light and virtually allows entire visible blue light to pass through anterior chamber structures and reach the retina.

3. Increases macular degeneration risk

Increased exposure to blue light may result in increased macular degeneration risks.

The fact that eyes cannot block the blue light from reaching the retina plays a significant role here, because studies have shown that increased blue light exposure can cause damage to the light-sensitive cells present in the retina.

This damage results in changes that mimic damages caused by macular degeneration, which results in permanent vision loss.

Ophthalmologists and other healthcare experts are showing increasing concerns about the effect of blue light on the eyes. According to them, blue light exposure from various digital devices such as smartphones, computer screens, etc. can increase the chances of a person developing macular degeneration in the later stages of life.

More research is, however, needed to quantify the amount of blue light (manmade and natural) that can be deemed as harmful to the retina.

4. Increase digital eye strain

Since the blue light scatters more than the visible light, it cannot be easily focused. When working on digital devices or viewing the computer screen, this unfocused light reduces the contrast and contributes to eye strain.

Researchers have determined that lenses that can block blue-violet light increase contrast significantly. Therefore, using yellow-tinted glasses on computers and digital devices can help in enhancing comfort while watching digital devices for long periods.

5. Can impact cataract

If you have cataracts and planning to undergo surgery, check with your surgeon the type of IOL that will be used and how much protection it will offer from blue light.

Once the surgery is completed, you can opt for special eyeglasses which have lenses equipped with blue light filter. This is more important if you have to spend several hours in front of a computer or any other digital device.

Not Everything is Bad

It’s true. Blue light also has certain beneficial effects.

1. General health

Exposure to blue light in limited quantities is wonderful for human health. High-energy visible lights have been known to increase memory, boost alertness, elevate mood, help memory, and improve cognitive functions.

2. SAD

In fact, one of the most well-documented uses of blue light as a therapeutic agent is in treating seasonal affective disorder or SAD. A type of depression, SAD, is related to seasonal changes. It typically starts in the autumn and continues through winter.

Blue light therapy involves the emission of a bright white light containing a higher amount of high-energy visible blue light rays.

Circadian rhythm

Blue light also plays a significant role in regulating the circadian rhythm — your body’s internal clock. Exposure to adequate blue light during daytime helps in maintaining a healthy circadian rhythm.

Too much exposure during late nights can disrupt this clock leading to increased fatigue and sleepless nights.

Protection From Blue Light

Some of the ways to address the increased exposure of blue light are:

Reduced screen time

Decrease the amount of time spent before a computer or television. Taking regular breaks can give your eyes some rest.


Use screen filters for computers and other digital devices. They help in decreasing the amount of blue light emitted.

Anti-reflective lenses

These lenses not only increase contrast and reduce the glare, but it also effectively blocks blue light.

Computer glasses

Using yellow tinted eyeglasses for computer glasses can effectively address issues with blue light.

Intraocular Lenses

Check with the surgeon to see if the new IOL has features that will help in blocking the blue light from reaching the retina.
About author
Deepak Warrier
The author Deepak Warrier has more than 14+ years of experience in Medical Transcription and has good expertise in fact checking and presenting medical and health related information. He has rich experience in handling files prominently related to cardiology, psychology, and general medicine.

More in Health