- Amy Vass - ABOC, Optician
FL-41: Migraine And Light Sensitivity Glasses
Updated: Jun 19, 2020

We’ve all heard the term ‘rose-colored glasses’. But, did you know there are actually rose-colored glasses that can help with certain vision and medical conditions? It’s true! The filter, or tint, that gives them their rosy color is called FL-41. The FL-41 filter can be applied to Rx, or non-Rx, glasses lenses. This filter can help ease some of the negative effects of conditions such as:
-Light triggered migraine headaches
-Blepharospasm
-Light triggered seizures
-CVS (Computer Vision Syndrome)
-Indoor light sensitivity
-Blue light sensitivity
-Other light-sensitive/triggered condition

FL-41 was developed in the 1980s by a Dr. Arnold Wilkins of Cambridge University (UK). He had patients who were suffering from eye strain and headaches due to fluorescent lighting. He and his team named the tint “Fluorescent-41,” or “FL-41.”
Researchers at The Birmingham and Midland Eye Centre (UK) also looked at FL-41 glasses for children. The researchers found that wearing the FL-41 filter improved the light sensitivity in these children, as well as lessened the frequency and severity of their migraine headaches. Since that time, FL-41 filtered lenses have been used to treat these and other light-sensitive/triggered conditions.

Q&A
How does the FL-41 filter work?
Although we are not completely sure how the FL-41 filter works, it does seem to have something to do with the wavelengths/spectrums of light that are filtered out. FL-41 filters out certain wavelengths of blue and green. These colors are thought to be particularly bothersome to patients who suffer from light-sensitive/triggered conditions. By blocking these wavelengths of light, this filter also improves contrast and sharpness which increases visual acuity.
Are there any side effects from wearing FL-41 filter?
There are no known side effects from wearing the filter.
Can the FL-41 filter be worn indoors and outdoors?
Yes - the FL-41 filter can be worn indoors and/or outdoors. However, that having been said, the FL-41 filter is typically used, (and seems to be most beneficial), in an indoor arena and setting. We’ve found that most patients prefer polarized sunglass lenses out of doors. There are a few, though, who do prefer the FL-41 filter outdoors as well as indoors. If you’re wanting them for multiple settings/environments, more than one pair will typically be needed.
If you feel you could benefit from the FL-41 filter, come see us at Frameworks Eyewear. Let us help make your view of the world a more rosy one. ;-)

Sources:
1.University of Utah Health/Moran Eye Center-Migraines and FL-41 Tinted Lenses/Web Accessed: 01 January 2020.
https://healthcare.utah.edu/moran/optometry/fl41-lenses.php
2.FL-41: Effective Migraine Treatment Or Just Hype?/October 4, 2019/Web Accessed: 10 January 2020.
https://migrainebuddy.com/relief/2019/10/4/fl-41-effective-migraine-treatment-or-just-hype