Although we are not completely sure why FL-41 improves light sensitivity, it seems 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 with light sensitivity. By blocking these wavelengths of light, this filter also improves contrast and sharpness, which increases visual acuity.

Leica microscopes providing phase contrast are commonly used in life science research for the visualization, analysis, and documentation of biological structures and cellular processes.

Currently, there's only one type of Avulux lens that has been specifically designed to be worn indoors or outdoors. They are currently not available as a polarized lens.

A phase contrast microscope is similar to a conventional widefield microscope, except it uses an aperture in the shape of an annulus and a quarter-wave (λ/4) phase plate. The annular aperture is placed between the light source and condenser lens and the phase plate after the objective inside the microscope optics. Ring-shaped light that passes through the aperture is focused by the condenser onto the biological specimen to be observed.

The John A. Moran Eye Center and its Neuro-Ophthalmology specialists are at the forefront of the treatment of the light sensitivity associated with migraine as well as other light-sensitive conditions:

Unlike FL-41, Avulux has the appearance of a neutral, gray tint and does not distort colors. Avulux filtering technology is integrated into the material used to create the lenses, ensuring that each lens has optimal transmission characteristics, the same appearance, and maximum performance. Wearers will also notice that the filtering characteristics of Avulux lenses improve contrast and sharpness.

For forensic applications concerning the evidentiary investigation of paints, pigments, textiles, fibers, and human tissues, Leica microscopes offering phase contrast are very useful solutions.

Widefield microscope

Avulux and FL-41 are not the same. FL-41 was originally developed for patients with fluorescent light sensitivity and predominantly filters blue light. It does not affect the red-orange light (590 nm), which is also critical for reducing light sensitivity. Avulux lenses block the wavelengths of light that are most bothersome to patients with migraine and transmit those wavelengths of light, especially green light, that are more comfortable. Unlike FL-41, Avulux has the appearance of a neutral, gray tint and does not distort colors. FL-41 lenses are made by hand, which means there can be more variability in the appearance of the lenses. Avulux filtering technology is integrated into the material used to create the lenses, ensuring that each lens has the perfect transmission characteristics, the same appearance, and maximum performance. Wearers will also notice that the filtering characteristics of Avulux lenses improve contrast and sharpness.

In tests of FL-41-filtered lenses against conventional gray sunglasses and standard rose-tinted spectacles, Moran researchers found that the majority of patients preferred wearing FL-41-filtered spectacles.

In collaboration with the University of Utah's Technology Licensing Office and University of Utah Professor Dr. Steve Blair, Moran Eye Center clinician-scientist Dr. Bradley Katz developed a filter that improves on FL-41 by more effectively blocking those wavelengths of light that can cause discomfort. This technology has been licensed from the University of Utah and was commercialized as Avulux lenses in 2023.

Some insurance plans do cover the cost of prescription eyewear. If your insurance plan does not cover prescription eyewear, we cannot bill your insurance carrier directly. However, you can request reimbursement for your Avulux purchase from your insurance carrier. You will likely need a letter from your physician saying that the lenses are medically necessary.

Avulux lenses are the only lenses approved by the U.S. FDA to be marketed as a general wellness tool that may, as part of a healthy lifestyle, help people living with migraine.

The knowledge portal of Leica Microsystems offers scientific research and teaching material on the subjects of microscopy. The content is designed to support beginners, experienced practitioners and scientists alike in their everyday work and experiments.

Leica microscopes capable of phase contrast make a difference for the study of transparent and colorless minerals, crystals, and polymers.

Brightfield microscopy normally only provides a low-contrast image of many transparent biological specimens where few details are distinguished. One way to enhance contrast with brightfield microscopy is to use selective stains, but such stains are often toxic to living cells. A phase contrast light microscope offers a way to view the structures of many types of biological specimens in greater contrast without the need of stains. The contrast method exploits differences in optical density between structures of a specimen that lead to a phase shift of the light that interacts with the specimen and its structures.

The FL-41 filter can be applied to most any lens material – providing it DOES NOT have any coatings applied to it beforehand, i.e., no hard coats, scratch coats, UVA/UVB filters, anti-reflective (AR) treatments, or other tints/filters, etc. These coatings, if wanted, can be done after the FL-41 filter has been applied to the lenses. If you want a dark FL-41 filter, CR-39 plastic would be the best lens material, as it is a more porous material and can absorb the filter more deeply. Light to medium FL-41 filters can be done on pretty much any lens material.

Most insurance plans, including Medicare and Medicaid, do not cover the cost of adding filters to lenses. However, there may be exceptions, so contact your insurance provider.

Leica microscopes offer phase contrast for the study of cells or tissues concerning various life-science and forensic applications. Phase contrast can also be useful for certain material and earth-science applications.

The phase contrast method for microscopy was developed in the 1930s by the Dutch physicist Frits Zernike. After 1942, it became a widely used microscopy technique. In 1953, Zernike was awarded the Nobel Prize for Physics. For more details, refer to the articles: A Brief History of Light Microscopy – From the Medieval Reading Stone to Super-Resolution & Phase Contrast

The researchers found that wearing the FL-41 filter improved the light sensitivity in these children and lessened the frequency and severity of their migraine headaches. Since then, FL-41-filtered lenses have been used to treat these and other conditions.

Darkfieldmicroscopy

Light sensitivity is determined by a specific class of cells in your eye, the intrinsically photosensitive retinal ganglion cell (IPRGC). These cells synchronize your body to the light/dark cycle of the day and help your body adjust to jet lag. These cells also regulate light sensitivity by monitoring a blue-green wavelength (480 nm) and a red-orange wavelength (590 nm). Avulux lenses reduce light sensitivity by blocking these two wavelengths of light. Green light is most comfortable for migraine patients, and Avulux lenses transmit these wavelengths.

Most often biological specimens and tissues are observed with a phase contrast microscope. A large variety of biological specimens can be observed with phase contrast from fixed specimens to living cells and tissues. For examples, refer to the articles: Phase Contrast & Optical Contrast Methods

If you don't wear prescription glasses, Avulux offers non-prescription lenses. You can wear these non-prescription lenses over your contacts if you wear contacts. Although not yet available, Avulux is developing contact lens products that will use nanoparticle technology.

Although you can wear Avulux lenses just when you have a headache, experience has shown that they are more effective when worn continuously to prevent a headache from starting. Some patients wear them when they know they will be exposed to triggering lights like non-incandescent artificial light (including fluorescent and LED lights) and computer screens. Avulux lenses are not recommended for night driving.

Wearing sunglasses indoors can dark-adapt your eyes, making you more sensitive to light. Although it's fine to wear sunglasses outdoors, wearing them indoors can make you more susceptible to migraine symptoms and light-triggered pain. If you're currently wearing sunglasses indoors, wear Avulux for at least 2-3 weeks to allow your eyes to adapt to the lighter lenses.

Certain wavelengths of light have been shown to worsen migraine headache pain and even incite migraine attacks. Avulux precisely filters light at certain areas in the visible light spectrum. They can be worn indoors or outdoors without distorting how you perceive color and may help people living with migraine.

Not all products or services are approved or offered in every market, and approved labelling and instructions may vary between countries. Please contact your local representative for further information.

Portions of the ring-shaped light are diffracted by optically dense structures of the specimen and experience a negative phase shift of about λ/4. This phase-shifted, diffracted light bypasses the λ/4 plate. In contrast, the portion of the ring-shaped light that passes directly through the specimen non-deviated will hit the phase plate which causes a positive λ/4 phase shift. As the total difference in phase shift between the light diffracted by the specimen’s structures and that which passes through phase plate will be about λ/2, destructive interference will occur. Consequently, more optically dense structures will appear darker than those that are less optically dense.

The FL-41 filter can be worn indoors or outdoors. The FL-41 filter, however, is typically used and seems to be more beneficial in an indoor setting. The "FL" in FL-41 stands for "fluorescent." We’ve found that most patients prefer some type of polarized lens out of doors. There are a few, though, who prefer the FL-41 filter outdoors and indoors. Some will get one pair (lighter) for indoors and one pair (darker) for outdoors. If you want them for multiple settings, more than one pair will typically be needed.

Since the 1990s, the Moran Eye Center has studied and advocated the use of FL-41, a rose-colored tint first developed for patients with fluorescent light sensitivity and migraine. Researchers at the Moran Eye Center were the first to demonstrate the effectiveness of the lenses, which block certain wavelengths of light, for the treatment of benign essential blepharospasm. This neurologic disorder results in frequent blinking, squeezing of the eyelids, and difficulty opening the eyes.

Avulux lenses are the first to have been tested in a clinical trial and received FDA confirmation of classification to be marketed as general wellness tools, which may, as part of a healthy lifestyle, help people living with migraine. Preliminary research conducted at the University of Utah also indicates that Avulux may help patients with visual snow syndrome and SEES.

Avulux lenses block the wavelengths of light that are most bothersome to patients with migraine and transmit those wavelengths of light, especially green light, that are more comfortable.

Köhlerillumination

A phase contrast microscope is similar to a conventional brightfield microscope, except it uses an annular aperture in front of the light source and a quarter-wave phase plate after the objective lens.  For more information, refer to the article: Phase Contrast

You can use your FSA or HSA card to purchase Avulux lenses. Be sure to save your receipt in case your carrier requires proof of purchase.

No. There is no scientific evidence that blue-blocking glasses can help with migraines or other light-sensitive conditions.

Aided by funding from the Benign Essential Blepharospasm Research Foundation, Moran Eye Center researchers have found that blepharospasm and migraine patients suffer more from light sensitivity vs. people who do not struggle with these conditions. When these patients have their light sensitivity treated, their blepharospasm and migraine symptoms improve.

Criticalillumination

Phase contrast is an optical contrast technique for microscopy which makes unstained structures in the cells of biological specimens visible. Cell structures that appear transparent with brightfield illumination can be viewed in high contrast and rich detail using phase contrast. Differences in optical density between structures in the cell can cause light that interacts with them to attain a phase shift. This phenomenon is the basis of phase contrast. As a result, more optically dense structures will look darker than less optically dense ones.

Research conducted at the University of Utah indicates that Avulux lenses may be helpful for patients with visual snow syndrome and SEES. Avulux lenses may be helpful for other light-sensitive conditions, but more research needs to be done before we can recommend Avulux for other conditions.

Avulux lenses are available for almost any prescription. If you're not sure, contact Avulux.com with a copy of your prescription and the company can verify that it's available.

FL-41 was first described in a research project in Birmingham, England, in the early 1990s. In this study, children with migraine headaches wore "boysenberry-ish" colored FL-41-filtered spectacles.

Avulux lenses are the product of eight years of research and development and multiple independent clinical trials. Clinical studies performed with Avulux migraine glasses show that by precisely filtering light, they may help people living with migraine.Avulux conducted a clinical trial that showed these lenses can reduce migraine-associated pain and light sensitivity. The results of this research may be found here.