Eyes during lockdown – Part 2.2

How to protect your vision from the ill effects of digital exposure during the current lockdown? 

While it will not be fair to ask you to stop your digital device use given the current situations, let’s see how we can minimize it and when we do use screens, how can we best use them to cause minimum ocular stress.

I shall be sharing one point everyday with you all. 

2. Protection from light emitted by display devices

Older CRT monitors did emit very low levels of UV light, which may have led to eye damage over time, (there is not enough research to prove it). However, LED and LCD flat-panel monitors, most commonly found on laptops, desktops, tablets and mobile devices today do not emit any UV radiation. 

What they emit is HEV (high energy visible) Light or Blue light 

Blue Light is present in natural daylight. Basking in light is one of our basic needs. It can boost our energy, elevate our mood and is important for regulating our circadian rhythm – our natural wakefulness and sleep cycle. But too much light at the wrong time can be harmful.

Today’s electronic devices use LED back-light technology to help enhance screen brightness and clarity. These LEDs emit blue light waves.  Smart phones, computers, tablets and flat-screen televisions are just among a few of the devices that use this technology. Because of their wide-spread use and increasing popularity, we are gradually being exposed to more and more sources of blue light and for longer periods of time than we would be naturally from sunlight.

While these sources contain a small amount of blue light compared to the sun, just think of the amount of time we spend on these devices and how close we put our faces to them.

The eye is not very good at blocking blue light

Anterior structures of the adult human eye (the cornea and lens) are very effective at blocking UV rays from reaching the light-sensitive retina at the back of the eyeball. On the other hand, virtually all visible blue light passes through the cornea and lens and reaches the retina.

Blue light contributes to digital eye strain

Because short-wavelength, high energy blue light scatters more easily than other visible light, it is not as easily focused as its longer wavelength counterparts.

This unfocused visual "noise" reduces contrast, creating glare and flickering, contributing to digital eye strain. Since sharpness and visual contrast are affected, the eyes have to work harder to see clearly. After extended periods of time this can result in headaches, blurred vision, dry eyes, and mental and physical fatigue.

Sleep Disruptions 

Natural blue light in the atmosphere is known to help regulate the body’s circadian rhythm (which controls your sleep cycles), to boost your mood, level of alertness and to improve memory and cognitive function. However, prolonged exposure to artificial sources of blue light has been shown to reverse these positive effects.

Research has found that exposure to blue light suppresses the production of Melatonin (the hormone which regulates the sleep-wake cycle) , causing disruptions in the circadian rhythm which affects sleep, as well as an increased risk of depression. Studies show that using a digital device before bedtime can negatively impact there amount and quality of your sleep.

A study by the University of Toronto found that those who wore glasses that blocked blue light wavelengths produced more melatonin than those who didn't during night shifts. Other studies have found that blue wavelengths suppress delta brainwaves, which induce sleep, and boost alpha wavelengths, which create alertness.

Blue light exposure may increase the risk of macular degeneration?

The fact that blue light penetrates all the way to the retina (the inner lining of the back of the eye) should be studied further. Laboratory animal studies have shown that too much exposure to blue light can damage light-sensitive cells in the retina.

However, so far, all research on blue light emitted from electronic devices causing macular damage in human eye is contradictory and inconclusive. Still many eye care providers are concerned that the added cumulative blue light exposure from computer screens, smartphones and other digital devices might increase a person's risk of macular degeneration later in life. More research is needed, though, to determine how much natural and man-made blue light is "too much blue light" for the human retina. 

How Can You Protect Yourself from Blue Light Emissions?

As the dangers of blue light from digital devices emerge, more and more options are becoming available to protect your eyes. The eyes have very limited natural ability to block out blue light radiation so we need to be aware of blue light exposure and how to minimize it.

Computer glasses with Blue-blocking lenses, coatings and filters are a good solution for those working on a computer for long periods of time each day. Research has shown that lenses that block blue light with wavelengths less than 450 nm (blue-violet light) increase contrast significantly. Therefore, computer glasses with yellow-tinted lenses may increase comfort when you're viewing digital devices for extended periods of time.

Additionally, there are filters available for devices such as computers, smartphones and tablets, to reduce the amount of blue light radiation that can reach your eyes. 

The easiest way to reduce blue light exposure is to take frequent breaks when working on a computer and to reduce screen time overall, especially after dusk.

Stay safe, Stay healthy

Mithali Paranjape +919890147825

                                    | Paranjpe Vision Care, F.C. Road | Paranjpe Eye Care. Karvenagar | +919823351184 |