Buying laser glare protection to shield your team of law enforcement officers from laser strikes is a prudent decision. Laser glare protection functions as a filter that reduces the power of a laser beam to a level safe to the human eye. These filters are essential to prevent laser light from distracting, dazzling, and flash-blinding your officers, while allowing them to maintain situational awareness and therefore operational capabilities. Not all laser glare protection products on the market are created equal. For example, some offer great protection, but at the expense of transparency. Visibility is a crucial factor, among others, to consider, particularly for nighttime operations. Here is a list of seven things you should consider when purchasing laser glare protection for your team:
1. Type: Dye-based vs. Holographic
Most of the laser filters currently on the market are based on dyes. Dye-based technology has for years been used to make safety goggles for scientists working with laser equipment, long predating its employment in producing eye protection devices for people at risk of laser exposure outside laboratory settings, such as pilots and police officers. Dye-based filters block laser light through absorption. New alternative entries to the market are holographic filters that work by reflecting, rather than absorbing, light.
2. Form: Built-in vs. Add-on
Regardless of the type, laser protection filters generally come in two forms: ready-to-use devices (for example, eyeglasses and visors) and self-adhesive, flexible strips that can be applied to face or body shields. Of the two forms, strips offer greater adaptability and cost-effectiveness, because they can be easily used to enhance existing defense equipment with laser protection. Therefore, the strip form may be a better option for your officers, as they can attach these strips to the equipment suited to their specific operational needs.
3. Selectivity: Which color is blocked
Laser filters are highly selective in terms of the colors of light they can block. For example, a green-light filter blocks only green light and is ineffective at filtering out light of any other colors like red and blue which will pass right through a green-light filter. The color of a given light depends on its wavelength (measured in nanometers or nm).
Most consumer green laser pointers produce green light at a wavelength of 532 nm, and thus green laser filters are generally rated for this wavelength. Because the human eye is innately most sensitive to green light, green light appears much brighter than red light with the same power. As a result, green laser light can produce the most dramatic startling and distracting effect on law enforcement officers, especially in low-light settings when the pupils are dilated and can receive more light. Therefore, you should treat green laser light as a primary concern.
4. Transparency: How Much Visible Light Can Pass Through
Another element to consider when buying a laser filter is its transparency. This characteristic is crucial to officers dealing with hostile situations at night. Visible light transmission (VLT) is an indicator of transparency. This specification, expressed as a percentage, tells you how much visible light can pass through a laser filter. The higher the VLT, the more visible light can pass through the filter, and therefore the higher the transparency. A laser filter with a VLT of 60% allows 60% of the visible light to pass.
To combat the projection of multiple laser beams oo various colours simultaneously, manufacturers have developed laser filters offering protection from a broad range of colors, or wavelengths, of light. These filters generally have lower VLT, meaning that they may significantly reduce visibility and thus potentially put your officers in danger. Thus, low transparency (“low VLT”) is an inherent problem associated with dye-based filters. In contrast, holographic filters offer high transparency. This feature allows your officers to have a clear view of their surroundings and helps them identify potential threats.
5. Strength: How Much Of The Laser Light Is Blocked
Not all laser filters are created equal. Some can weaken the target light more than others. Optical density (OD) tells you how much a filter can reduce the power of a laser beam. It is given as a number and is color (or wavelength)-specific. The higher the OD, the more the filter can weaken the light, and the better the protection. For each increase of 1 in OD, the light can be weakened 10 times more.
It is important to note that OD is inversely proportional to VLT. This means that the higher the OD (that is, the protection), the lower the VLT (that is, the transparency), and vice versa. Thus, there is a trade-off between protection and visibility, and having both is problematic. Dye-based and holographic filters are comparable in terms of their OD numbers: they offer similar levels of protection from laser beams.
6. Angular coverage
Laser beams can strike law enforcement officers from all angles. The angle at which a laser filter can block laser beams is measured in angular coverage (AC). Most dye-based filters offer total AC, meaning that they are effective at blocking laser beams coming from any angle. Due to its structure, a holographic filter has a narrower AC, that is, it can block only laser beams coming from certain angles, generally within the central field of view. In practice, this limitation may be mitigated by movement.
7. Installation: Coverage of the Normal Line Of Sight
Installation applies only to the strip form of laser filters, as ready-to-use laser filters can be used right out of the box. A dye-based strip is recommended to be installed onto a face shield slightly above the wearer’s eyes. This allows the wearer to see through the face shield when there is no danger. Under a laser attack, the wearer dips their head down to position their eyes directly behind the strip for protection. This approach may be problematic for law enforcement officers, especially at night. First, for the strip to work, the officer needs to intentionally adjust their head position. Second, once the officer hides their eyes behind the strip, considerable visibility (due to the dye-based strip’s low transparency) will be lost, which could undermine operational competence.
On the other hand, thanks to its high transparency, a holographic strip can be fitted onto a face shield at the same level as the wearer’s eyes without substantially reducing their visibility. This means that a holographic strip can provide constant protection from laser beams without requiring any action from the wearer. This “always-on” benefit will help law enforcement officers tackle perpetrators head-on.
In summary, laser glare protection affords law enforcement officers both safety and operational benefits. While they provide similar levels of protection from laser beams, holographic filters like metaAIR® for Law Enforcement are sustainable, transparent and can be tailored to suit your individual needs, including multiple-wavelength glare protection, color balancing, and installation customization for equipment with flat or cylindrically curved surfaces.
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