Blue light: What it is, why it matters, and should I be concerned?

Author: Matthew Pennel, Optician

There is currently a lot of talk about blue light, blue light blocking glasses, and apps that reduce blue light from digital devices. Some push blue-light blocking lenses as “absolutely necessary.” Some think people just want to make money selling something that people don’t really need. I’ve reached a conclusion using a combination of feedback I’ve received from the numerous patients I’ve helped over the years, as well as information from continuing education classes and articles I’ve simply been interested in reading. In my opinion, there is a certain amount of credit to give to both perspectives, with the truth on whether a person would benefit from lenses that block blue light based mostly on their work environment and subjective experience. 


Before we get any further, I should clarify exactly what blue light is, what the effect on us is, and where it comes from. Blue-violet light is the highest energy wavelength of light that we can see, ranging from around 380 to 450 nanometers. This is the wavelength that blue light filtering glasses are generally designed to reduce, and the primary advertised sources of blue light are digital devices, LEDs, and fluorescent lights. Blue light can be irritating to our eyes, particularly when we’re exposed to it constantly for a long period of time. It is also worth mentioning that the single biggest source of blue light is the sun. It emits around 30 times more blue light than our LED phone, computer, and television screens. Sunglasses block blue light very effectively, but it’s still good to confirm that your sunglasses also block 100% of UV light, as some do not.


Some people or companies seek to make blue light seem terribly detrimental to your eye health in order to make money selling a product. For all we’ve heard on blue light and the associated dangers, there isn’t yet enough quality clinical evidence of serious danger from blue light to draw a solid conclusion from, despite the many studies that have been done. Put simply, we don’t know for sure whether blue light exposure causes any kind of permanent damage to the eye. It’s possible that it is harmful, or it could simply be an irritation with no long-term harm.


Some people are more sensitive to blue light and would notice a substantial increase in comfort by reducing it. I’ve heard a lot of people say they notice a big difference in their ocular comfort while using lenses designed to limit blue light exposure. I’ve also heard some say they notice no difference. I am, like many others, somewhere in the middle. I notice my eyes are a little less tired at the end of the day when I’m wearing lenses that block some blue light, so I like them.


The reduced eye strain that blue light blocking lenses offer many people is reason enough for me to offer this as a comfort product. If you were to come into our office with questions about blue light and lens options, I’d be more than happy to go over them with you, whether you’re asking simply out of curiosity or so you can make an informed decision as to the best product to meet your needs.


We’d love to see you for an eye exam, glasses, or both at First Sight Eye Care, located at 2126 1st Ave S in St. Pete. 


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