Before introducing artificial light, we only had one source of light: the sun. After sunset, people tend to spend their time in relative darkness. However, now that we have artificial light, we take it for granted. It is a virtually unchallenged piece of conventional wisdom that exposure to blue light affects our biological clock (circadian rhythm). Blue light is one of the environment-friendly lights, but if children have less exposure to sunlight, it could affect the growth and development of their vision.
Smartphone displays are impacting our eye health. Here are a few things you can do to limit the impact.
Blue light from smartphones can cause blindness and hurt our vision, as proven at the University of Toledo. Blue light can damage your cells in the retina. As a result, blue light generates a toxic chemical that damages our photoreceptors. If your photoreceptor dies, it cannot be restored.
Many smartphone manufacturers also feature a reading mode or global eye protection, which filters blue light by changing the color temperature and representation of the color. Blue light is not just emitted from smartphones; it also comes out of TVs, but there is a difference in the amount of exposure.
Using your smartphone is worse than sitting in a dark room. It also affects sleep time, which is also called the circadian rhythm. It slows down melatonin production. Melatonin is a hormone that regulates sleep. Green, yellow, and red lights do not affect our retina; blue light can kill any cell type. Blue light is relatively high in energy compared to others, and blue light has a shorter wavelength. Blue light from natural and artificial sources helps you feel energized and focused.
Most mobile apps use a white interface, where white light contains all the colors of the spectrum, including “blue.” Also, LED screens use blue LEDs as a base to combine with phosphorus chemicals to produce a white color. The problem is a weak immune system, poor memory, and weight gain. At the same time, UV-reduction eyewear has been on the market for a while.
What is blue light?
Every color has its wavelength, and blue light is quite beneficial for the human body during the daytime because it helps us boost attention, reaction time, and mood. At night, it is less helpful than during the day, and blue light at night is said to be one of the most disruptive. Blue light has wavelengths between 400 and 450 nanometers (nm).
This light is of most concern because it has more energy per photon than other lights in the visible spectrum, and therefore it is more likely to cause damage when absorbed by various cells in our body.
Companies have addressed this issue by creating warm-toned “Night Mode” settings on gadgets and glasses that claim to block blue light. Since your body is dictated by the circadian rhythm (a set of time-dependent physical, mental, and behavioral shifts), it is essential to be mindful of the impact of blue light on your body at different times of the day.
Eye strain due to blue light.
Some people experience discomfort when they stare at a screen for hours at a time. This is called digital eye strain. It occurs because most of us blink less when looking at a screen, which causes eye strain and dry eyes. However, it is not something that causes lasting damage and can be easily prevented.
Symptoms of digital eye strain include:
- Dry eyes
- Sore or irritated eyes
- Tired eyes
- Headaches
- Facial muscles fatigued by squinting
It is suggested to take regular breaks using the 20-20-20 rule. Every 20 minutes, take your eyes off the screen and look at an object at least 20 feet away for at least 20 seconds. Additionally, you can use artificial tears to refresh your eyes when they feel dry.
There is also no risk of age-related macular degeneration or blindness. The amount of blue light emitted from electronic devices is not harmful to the retina or any other parts of the eye.
The best source of blue light is the sun, not screens.
Although people often associate blue light with computers and phones, the largest source of blue light is sunlight. Other sources include fluorescent lights, compact fluorescent light bulbs, and LED lights. However, excessive exposure to ultraviolet light from the sun increases the risk of eye diseases, including cataracts, growths in the eye, and cancer. Not getting enough sun could also increase the risk of myopia (nearsightedness) in teens and young adults.
- It helps you stay alert.
- Boosts memory and cognitive function
- Potentially improves seasonal depression
- It helps with some skin conditions.
Effects of Blue Light on Sleep and More
Blue light has a significant effect on sleep and can potentially cause diseases such as cancer, diabetes, heart disease, and obesity. Even small amounts of electronics with screens that have enabled energy-efficient lighting all contribute to some amount of exposure to blue wavelengths.
Blue light is one of the most powerful lights that can suppress melatonin, and the melanopsin pigment (a pigment that helps eye cells assess light brightness) is particularly sensitive to shorter, more excellent wavelengths like blue light, affecting the body more dramatically than other hues.
Daylight keeps a person’s internal clock aligned with the environment.
Humans have slightly different circadian rhythms, with an average length of 24 and one-quarter hours. People who stay up late have slightly longer rhythms, and those who wake up earlier have shorter rhythms than 24 hours.
Effects of light and poor sleep exposure
People who work night shifts are exposed to the most light at night and often experience symptoms of diabetes, heart disease, and obesity. Although studies indicate a correlation, there is no firm evidence of how nighttime light exposure causes these conditions or why it is so bad for humans.
Even for some people who show increased blood sugar levels, exposure to light suppresses the secretion of melatonin, a hormone that influences circadian rhythms. Even dim light can interfere with a person’s circadian rhythm and melatonin secretion. Light at night is one of the reasons so many people don’t get enough sleep, and short sleep increases the risk of depression as well as diabetes and cardiovascular problems.
Block blue light.
Two kinds of goggles are available: inexpensive sunglasses with orange-tinted lenses that block blue light but also block other colors, which are unsuitable for use indoors at night, and glasses that specifically block blue light, which could cost up to $80.
Another way to protect yourself from blue light is to use fluorescent LED lights, which produce a fair amount of light in the blue spectrum. There are plenty of reasons other than sleeplessness not to spend all your time staring at screens, as possible mental health consequences may correlate with a sedentary lifestyle.
How to Protect Yourself from Blue Light at Night
- Use dim red light for night lighting, as red light shifts the circadian rhythm and suppresses melatonin.
- Avoid bright screens for 2–3 hours before bedtime.
- Consider wearing blue-blocking glasses or installing blue or green filters on your devices if you work at night.
- Exposure to sunlight during the day boosts your ability to sleep at night.
A dark room is the best environment for sleeping, as it blocks out light sources. Maintaining a room temperature between 65°F and 68°F, limiting intermittent noise, and sticking to roughly the same sleep and wake times each day to get quality rest are suggested. While we know less about blue light, its effects are still being researched.