Mojo BluBlock Tints with Light Transmission Details and Spectrograms
Steve Mower - August 2018
Our innovative Mojo BluBlock Tints are designed to provide various degrees of blue light filtration depending on your particular needs. Lens tints are "filters". Let's define some terms:
Lens Tints (Lens Filters): Tinted lenses have been around for hundreds of years. The tints we are dealing with are tints/dyes that are applied to optical grade lenses. These lenses have traditionally been CR-39 resin lenses. We use MojoPoly lenses which are a type of tint-able polycarbonate that filters UV light to 400nm. The lenses are submerged into a heated tint bath and absorb the tint/dye. The type of tint combinations and the time submerged, determines how infused the lenses are. This creates a lens with a filter to absorb light in different wavelengths. Tints that are applied to our lenses filter out a percentage of light across areas of the spectrum.
Light Blocking Lenses: Lenses that have cut-offs have either very highly saturated tints or are manufactured with dyes that are infused in the lenses. These lenses will block any light below a certain point. Some people with various vision problems, like these intense tints and find them beneficial. Most people find them to be annoying to see through. These types of tints are considered "Therapy" tints. Our BPI 500/550 Orange Red Tint is an example of this. Lenses with this tint (which are CR39 not poly) are saturated to the point where all blue light and more is filtered.
UV/HEV/Blue Light Safety Range: The optical industry has recognized for years that exposure to UV light is damaging. HEV High Energy Visible blue light is now being recognized as being damaging with high exposure, and contributing to Computer Vision Syndrome issues. HEV blue light is from ~390nm to 445nm. Our goal is to create tinted lenses that provide wearers with the best protection from UV and HEV blue light allowing the beneficial part of the blue light spectrum through. This results in full protection and provides lenses with the best look and feel to the tint.
The Wertheim Factor: Provides a numerical value defining the balance of UV/Total Blue Light filtration (not just HEV), and the beneficial light allowed through the lens. We want the highest Wertheim Factor and the highest blue light filtration percentage.
Our Testing Methods: We tested many lenses with many combinations/formulae of tints. We narrowed down to the best, and then generated the spectrograms below using a BPI Spectrometer from Brain Power Inc, the leading manufacturer of lens tints, tint systems and spectrometers.
The BPI Spectrometer uses standards set forth by the American National Standards Institute (ANSI). These standards include defined parameters for areas of the EM spectrum. The ANSI limit for UV is to 380nm, the safety acceptance limit for lenses that filter UV light. (UV400 is even better.)
For blue light, the BPI Spectrometer averages a range over 390nm to 550nm, centered at 470nm. We use MojoPoly lenses in zero power to tint and test. All tested at ~400nm for UV-A and B. Tolerances are +/- 1%.
These spectrograms show light transmission/filtration in various parts of the spectrum through a lens filter.
The graph shows:
- Vertically ^ percentage of light
- Horizontally > the light spectrum from
- The black curve shows light transmittance through the filter from 390nm to 700nm
- The blue section (block) is the blue light spectrum from 390nm to 500nm up to the filtration%
- The blue curve is the blue light spectrum as measured and averaged by the measuring device – BPI Spectrometer, which measures the blue light averaged from 390nm to 550nm centered at 470nm.
- < 390nm is UV Light
- From 390nm to ~445nm is considered HEV Blue light (the bad part of the blue light spectrum).
- From 445nm to 500nm is the beneficial part of the blue light spectrum.
- The box below the graph shows light transmittance by %
- Top: VISIBLE | RED | YELLOW
- Bottom: ULTRAVIOLET | GREEN | BLUE
The tint details below may change over time as we are always improving our products. As a matter of fact, the graphs and stats below represent a minimum for each lens tint. We tint and test each lens to meet or beat these minimums, both in blue light filtration and Wertheim Factor.
SPECTROGRAMS and LIGHT TRANSMITTANCE DETAILS:
|Mojo BluBlock Tints|