Effects Of Blue Light On Eyes

The use of smartphones or tablets especially while you are in your bed at night is known to be one of the reasons for sleep difficulty which will eventually lead to sleep deprivation. The blue light from your smartphone is said to cause damage to the eyes causing blurredness over time.

However, previously there was not any scientific evidence supporting this claim until a report that was published with the title, "Blue light excited retinal intercepts cellular signaling". The article stated how blue light from your smartphone can damage a user's eyes.

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Dr. Ajith Karunarathne, an assistant professor from the Department of Chemistry and Biochemist of the University of Toledo who wrote the report explained why blue light damages the eye since it affects our eye's retina.

The experiment that was conducted by their team clearly elaborated how everything happens.

How Does The Damage On The Retina Occur?

We all can see our surroundings with the help of certain parts of the eyes that send information in the form of signals to the brain. To understand how blue lights damage the eyes, it is crucial to know the mechanism of our vision starting from the light that enters the eyes all the way to the brain.

As light penetrates the cornea, the cornea will reflect this light and the iris will control the opening of the pupil that expands or constricts by permitting the amount of light that passes through it.

The iris is the part that gives colors to our vision like black, brown, blue, and such. When the light passes through the pupil, it will then focuses on the lens. Then the lens will focus those light on the retina.

Retina is a photosensitive tissue(sensitive to light) that contains photoreceptors. These photoreceptors will help convert that light into electrical signals and then pass through the optic nerves in the brain.

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In the brain, the information that has been received will be processed by the visual cortex. Without the existence of retina and photoreceptor cells, this visual information received by the eyes will not stimulate a biochemical reaction that activates the brain to process that information.

The ability of this retina is due to the presence of retinal molecules which is a form of vitamin A that will convert the light into electrical signals which will then be sent to the brain.

Experiments Regarding The Exposure To Blue Light

After understanding how light is processed by the eyes and brain as explained above, therefore it will be much easier to comprehend how blue light from smartphones damages the eyes.

According to Dr. Ajith Karunarathne, humans require a continuous supply of retinal molecules to be able to have a clear visual input. Photoreceptors cannot carry out their function without the presence of these retinal molecules.

In the experiment, scientists exposed the retina to several lights like blue, red, yellow, and green. They found that when the retina is exposed to blue light, it will trigger one reaction causing the retina to produce reactive oxygen species(ROS), a poisonous molecule that will kill the photoreceptors.

Aside from that, it should be known that these photoreceptor cells cannot be reproduced by our eyes. Due to that, if they were damaged, there will not be any new photoreceptor cells made.

To prove this theory, scientists repeated this experiment by exposing the retina to several other cells like cancer cells, liver cells, and neurons. It can be concluded that when you mix the retina with such cells that are exposed to blue light, those cells will also die.

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However, if those cells with the retina were to be exposed to other light like green, red, or yellow, it will not give any effect. In a nutshell, a retina that is exposed to blue light can make itself toxic and kill any type of cells.

What is scarier is that the retina is not only in our eyes but also in other parts of the body. Because of that, this toxic effect will also cause permanent damage to other parts of the body.

Tips To Avoid Eye Damages

Naturally speaking, human vision will decrease as we age older. This is due to macular degeneration which is a part of the retina that is responsible for our main vision which allows humans to identify faces and read.

This natural phenomenon generally starts in your 50s. With that in mind, exposure to blue light coming from smartphones will only expedite this macular degeneration.

In the study, it was found that alpha-tocopherol which is a derivative of vitamin E and a natural antioxidant found in the eyes and body can help stop these photoreceptor cells from dying.

But its effect also depletes as we get older due to our immune system becoming weaker. So it is always important to take care of our eyes and scientists suggest we reduce and avoid using smartphones in dark places as well as using black glasses to filter UV light and blue light.

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