Lately there has been a lot of talk about the effect that blue light has on eye health, eye fatigue and our sleep patterns. Before we start to discuss how blue light can affects us, it’s probably a good idea to define what blue light is and where it comes from.
What is blue light?
Blue light, also known as ‘near UV’ is in the wavelengths range of approx. 400 to 500 nanometres. Pre-industrial revolution blue light was primarily from one source only – the sun. These days we’re exposed to it from many artificial sources such as LED lighting, TV screens, computers screens and smart phones.
For a healthy life, we need some exposure to blue light but it’s highly likely that we’re getting far too much these days.
What effect does blue light have on the eyes and body?
Studies as far back as the early 1980’s showed intense exposure to blue light caused changes to the cells in the macula. More recent studies suggest that long-term exposure to blue light increases the risk of macular denegation and cataracts (blue light causes changes to the lens in the eye).
Away from the eyes, blue light is believed to have an impact on sleep patterns (our circadian rhythm). Historically the first light of the day was a trigger to wake us up. However, these days we’re looking at devices that emit blue light well into the night. The body can’t distinguish whether the light source is natural or artificial, confusing this light as a sunrise and affecting our circadian rhythm.
How can we reduce blue light exposure?
Having recognised the adverse effects that increased exposure to blue light can have on the eyes and body, the leading spectacle lens companies, namely Essilor and Hoya, have recently introduced blue light blocking coatings on their lenses. These coatings look like standard antireflection coatings but have the added advantage of blocking blue and UV light. So if you spend many hours a day in front of your PC, laptop, iPad or smartphone, especially if you work on these devices into the night, a blue blocking coating on your lenses could help reduce the risk of developing macular degeneration and/or cataracts, and improve your sleep patterns.
At Eyecare Plus Miami, we recommend and use Essilor's Crizal Prevencia antireflective coating. This coating can be added to any of the Essilor lenses. Crizal Prevencia lenses are the first lenses to offer selective protection from harmful blue light and UV rays, while allowing beneficial light through. For more information, please drop in to see us.
Article written by: Michael Quante - Optometrist, Eyecare Plus Miami