A hot topic that has presented itself in the optometric world lately has been blue light filtering technology. Everyone is wondering if and how harmful blue light is, what the effects of blue light are, and whether blocking blue light is worth it. Spoiler: blue light can be helpful at certain times.
This subject is usually discussed in the context of blue light filtering glasses. Recently, there has been a contact lens on the market that provides a moderate amount of protection from blue light from our screens and electronics.
Increased screen time has become a more significant part of daily life. With more emphasis on new contact lens technology, it was only a matter of time until breakthroughs came to market. This article discusses the basics of blue light and explores blue light-filtering glasses and contact lenses. I’ll also provide some tips on how to practice good visual hygiene.
Blue Light: Natural or Harmful?
Let’s start with the basics. The spectrum of light is divided into several portions, with the visible spectrum ranging from 400nm-700nm. This is incredibly narrow compared to the other types of light. The wavelength of light determines the colors we perceive. For example, shorter wavelengths (450-495 nm) are perceived as blue light.
Naturally, blue light is naturally present in outdoor settings. Studies have shown that it is most beneficial during the day–especially when it comes to mood, attention and how quickly we can react to certain stimuli. However, when present at night, blue light is disruptive. One of the most common non-natural sources of blue light is through LED screens like mobile phones, televisions, and other hand-held devices.
Blue Light Has Negative Effects On Sleep
One of the major problems caused by excessive blue light exposure at night is that it impacts our circadian rhythm. The circadian rhythm is the process that controls sleep and wake cycles in the human body. Blue light suppresses the production of chemicals that cause us to be sleepy. This is why it is harder to fall asleep when we use our phones right before bed. The same applies if we watch tv right before bed. These chemicals also help us stay asleep at night.
Other side effects of blue light late at night are insomnia, frequent waking at night, feeling constant fatigue from a lack of sleep, and irritability.
Besides disrupting sleep cycles, blue light has potentially been linked to other systemic and ocular health issues. Though there are still conflicting reports on the direct impact of blue light, sleep is valuable to maintain good systemic health. Many eye care providers argue that it is the way we use our devices rather than the blue light that causes harm.
However, some providers and patients swear by blue light-blocking glasses. They report a considerable decrease in eyestrain and headaches experienced when wearing blue light filtering lenses.
Besides using blue light filtering contacts, you can also use apps that filter out blue light to help regulate your sleep cycle for those who stay up late looking at screens. Other things like spending lots of time outdoors can also help regulate your circadian rhythm. The natural cycle of the sun setting and sun rising provide helpful signals to your body.
Blue Light Glasses: Do They Work?
Yes, blue light glasses effectively filter blue light. Blue light glasses have become an extremely popular option for people who want to reduce the potentially harmful effects of blue light exposure from electronic devices. Depending on which brand of glasses are used, lenses can filter anywhere from 5 to 60% of blue light rays.
Blue light filtering glasses can be distinguished from clear-coated glasses because they sometimes have a slightly visible blue tinge. However, you likely wouldn’t notice it unless you were going out of your way to look for it.
You don’t need to wear glasses or need a prescription to wear blue glasses.
Blue Light Contacts: Acuvue Oasys with Transitions
J&J’s Acuvue Oasys with Transitions contact lens has blue light filtering technology. Besides changing from clear to a darker hue due to its UV blocking tint when outdoors, the lenses have an added benefit: blue light filtering. When inside, the lenses can block up to 15% of blue light. When outdoors, the lenses can block up to 55% of blue light.
While these numbers are lower for indoor use (where it is arguably more important, especially in electronics), these are the first and only contact lenses currently on the market that offer such protections. And since there are potential links to blue light and early cataracts, the outdoor blue light protection may provide other eye-health benefits.
Currently, these lenses come in 2-week replacement intervals and are only available in spherical (non-astigmatism) prescriptions. With more research on blue light and its impact on humans and the visual system, there will likely be a greater push in the future for more options in brands and more effective contact lens technology.
If you need them, these are your best options for contacts for astigmatism.
Tips for Blue Light Exposure
Though there is inconclusive evidence on whether blue-blocking glasses or contacts can impact vision strain when using digital devices, there are some steps you can take to reduce the amount of eyestrain you can experience.
- Taking breaks every 20 minutes of electronic device use can significantly reduce the amount of discomfort you experience.
- This is termed the ’20/20 rule’. This means that for every 20 minutes you spend looking at a screen, you need to look away at a distant object for 20 seconds. This is simple, as it doesn’t require you to get up or move around. The distant object can be something as easy as a tree outside.
- A second tip is to take frequent, deliberate blinks when using electronic devices. People tend to blink less when looking at screens. This leads to dryness and blurry vision. Make sure to blink often! This is a simple task that can go a long way. If you find that your eyes get dry despite blinking, preservative-free artificial tears can also be used to lubricate the eye. Moist eyes are happy eyes.
- Wear glasses at the computer! Being properly corrected can reduce the amount of eye strain experienced and the associated symptoms.
- Shop for your blue light filtering glasses.
In conclusion, blue light has potentially harmful effects on the visual system and your sleep cycle. There are many different glasses brands available, but there is currently only one brand of lenses on the market that provides blue light filtering. For now, good visual hygiene when using computers is the safest bet to reduce eyestrain. The future of contact lenses is bright–however, your screens at night should not be!
Dr. Morgan Jones is a Doctor of Optometry (O.D.) completing a residency in ocular disease. She has experience in diabetic research, along with several years of clinical research. Along with being a community outreach leader and an avid mentor and tutor, she enjoys educating outside of clinic. Dr. Jones has a B.A. in Biology from Texas A&M University.