Laser Glare Protection (LGP) is primarily intended for pilots, to mitigate bright laser light. It has a different goal than conventional Laser Eye Protection (LEP) which has been used for decades in laser labs, industry, laser medicine and the military.

• The goal of Laser GLARE Protection is to reduce laser light brightness to a comfortable or manageable level. Usually it is not desired to block all of the laser light, since a pilot may need to see a laser source in order to report its location.

• The goal of Laser EYE Protection is to reduce or block laser light to a level that will not injure the eye. The laser light may still be very bright, or it may completely disappear.

Both LGP and LEP use the same materials and techniques. The difference is in the amount of light reduction, or Optical Density, which is desired to protect against the selected laser wavelengths (colors).

In almost all cases, Laser Glare Protection also happens to reduce laser light to a level that will not injure the eye. (The only exceptions might be for deep blue or dark red light that inherently does not appear bright to the eye even without LGP or LEP, but that could be above the Maximum Permissible Exposure. Consultation with a LGP manufacturer can determine whether this is even a problem, and if so, how best to address it.)

The photo-illustrations below give an idea of how LGP glasses work:

There are three main technologies used to make LEP and LGP eyewear:

• Dyes: The plastic used for lenses has a light-absorbing dye built in. Different dyes will absorb different wavelengths.
• Thin-film: Materials are evaporated in a vacuum chamber and are carefully deposited on the lenses, with precise thicknesses. By varying the materials and thicknesses, layers build up that can reflect desired wavelengths of light.
• Holographic: A holographic technique is used to create very thin layers in a material which is then laminated onto the lens surface. Similar to thin-film, these layers are designed to reflect desired wavelengths of light. (This technology is relatively new as of 2019; thus far only one company is producing holographic laser-protection eyewear.)

Each technology has advantages and disadvantages:

• Visible light transmission: For dye, the higher the Optical Density to absorb laser light, the lower the overall visible light transmission. For thin-film, increasing Optical Density has less of an effect on visible light transmission. For holographic, in general, increasing Optical Density does not adversely affect visible light transmission.
• Attenuation: Dyes attenuate a relatively wide spectrum, meaning that they absorb not only the desired wavelength of light, but about 25 nanometers on either side of that spectrum. For thin-film the attenuation on either side is about 15-20 nm. The holographic technology has a relatively narrow spectrum of about 8 to 13 nm on either side.
• Angle sensitivity: Dye lenses will absorb the same amount of laser light (or a little more), if the light comes in from an angle versus from the front. For thin-film and holographic lenses, they are most effective with light coming in from the front. Coverage is good for light from about 30 degrees to either side of front (perpendicular to the lens).
• Durability: Because the dye is uniform throughout the lens material, a scratch does not adversely effect the ability to absorb laser light. For thin-film and holographic, the coating or film can be scratched which reduces the ability to reflect laser light; this can be partially alleviated with additional protection layers and coatings.

The U.S. Federal Aviation Administration is aware of LGPs but currently does not recommend or require LGP use. Pilots who want to use LGP can do so -- subject of course to any rules applied by their airline or employer. Here are some tips:

• Determine the wavelength(s) to be blocked. Green is the primary color listed in FAA laser illumination reports. As of 2019, 532 nm green is the most common. It may be desired to protect against other wavelengths such as 445 nm blue or (as it becomes more available) 520 nm green. Each added wavelength can have an adverse impact on visible transmission and on color discrimination, so the number and type of wavelengths should be carefully considered.

• Determine the Optical Density. Pilots at greater risk – those closer to laser sources, who spend more time looking at or searching after the laser source – should choose a higher OD such as 2. Pilots who rarely encounter laser sources and/or those who are in fixed wing aircraft where the time of exposure is generally brief, should consider a lower OD such as 1.

• Shape, type, coverage, form factor. For LGP eyewear, “aviator” style glasses should be sufficient for most uses. Pilots wearing prescription glasses need to select LGP eyewear which fits over their glasses. Pilots at greater risk who are not bothered by goggle style eyewear may wish to consider this option for additional protection from light coming from the side and bottom (e.g., in a helicopter bubble). If helmets are worn, the LGP eyewear needs to be compatible.

• Compatibility with cockpit displays, caution and warning lights, and airport lighting. It is imperative that users first test the LGP in a safe aviation environment, under low-light conditions such as dusk or dawn as well as on a dark night. Testing under low-light conditions will help ensure that instrument lights will not be washed out by ambient light plus the visible light reduction of the LGP. Testing at night helps ensure that there is sufficient visual light transmission of the LGP even under very dark conditions. Pilots should experience and understand the effect the LGP will have on the airport lights, cockpit displays, caution and warning lights, and general visibility. This should occur on the ground, and in the air during non-critical flight phases. For two-pilot aircraft during flight familiarization, it is recommended that one pilot fly normally (without LGP) while the other pilot familiarizes himself or herself with the LGP’s usage and effects.

• Familiarization and readiness for use. All of the above steps may be meticulously followed, but the LGP is useless if it is not available and ready for quick use if a laser is seen or reported to be in the area. Pilots with LGP need to put them in a readily accessible location every time they will be flying at night. They should practice donning the LGP, in a safe situation during non-critical phases of flight. As with any piece of safety equipment, if it is not readily available then there is no safety.

Pilots should NOT rely on ordinary sunglasses or common “blue blocker” type glasses. Using sunglasses at dusk, night and dawn (when almost all laser incidents occur) could be unsafe. Blue blocker glasses have an effect on many different colors of blue and green. This may adversely effect how cockpit instruments and airport lights are perceived.

Pilots should also be cautious of Laser Eye Protection eyewear (“laser safety glasses”) made for laboratory use, which are not specified for aviation use. They may limit too wide a range of colors, or may not be effective against the most common laser pointer colors. Look for Laser Glare Protection eyewear intended for pilots.

Simulated use of general-purpose green-blocking glasses,
where 50% of broadband green light is blocked.
Note significant change in instrument panel colors.
Obviously, these should not be used for anti-laser purposes.

Laser Glare Protection eyewear should be immediately accessible to a pilot, due to laser illuminations being unexpected and usually brief events. However, LGP should not be routinely worn.

• LGP should be donned if a laser illumination happens during or prior to a critical phase of flight.

• It can also be donned if there is a reasonable expectation of a recent, active or possible laser illumination during or prior to a critical phase of flight. For example: news reports of incidents at a specific airport, reports from other aircraft in the vicinity, or notification by air traffic control.

For pilots in a 2-seat cockpit, there may be times where it is advantageous for one pilot to wear LGP and one pilot to fly without LGP. This decision would be best made by the organization using aircraft in an laser environment, and would be highly situation-dependent.

For other crew in the cockpit or on the aircraft, such as the Tactical Flight Officer for a police department helicopter, the use of LGP would be situation–dependent.

Laser Glare Protection eyewear is helpful, but LGPs are not a complete solution to the laser pointer problem. Some key reasons are:

• Anti-laser glasses can only protect against one or a few specific wavelengths of laser light. Glasses that protect only against a certain green, such as 535 nanometer green, may not be effective against 520 nm green or other colors such as red or the increasingly-common blue lasers.
• Anti-laser glasses will reduce visible light transmittance, so the view may be dimmer.
• In general, the more wavelengths (colors) that are protected against, the dimmer the view — compared with single-wavelength blocking glasses.
• Any laser incident may be over before glasses can be put on. (Or, if the pilot wears them all the time, this means that the glasses are unneeded well over 99.99% of the time.)

Obviously, pilots should not have laser light aimed at them in the first place. Also, pilots should know how to recognize and recover from a laser illumination, whether or not they happen to be wearing eyewear.

But appropriate LGPs, specifically designed for aviation use, can be helpful for pilots who might want to have an extra level of protection against common laser pointers. Any LGP should be safely tested on the ground or during cruise autopilot flight to ensure that the particular indicators and displays in the cockpit are still adequately visible when wearing the glasses.

It is then up to the pilot to decide whether to use these routinely, to use them only at certain airports, or to simply have them available in the cockpit in case laser incidents are reported by other pilots or ATC during a flight.

Additional information about LGPs is in this FAQ question.

A May 4 news release describes how the Air Force developed anti-laser eyewear for military pilots, and has tested a commercial version: Commercial Aviation Low Intensity or CALI. It is specifically designed so pilots can accurately read the control panel and still have anti-laser protection. One pilot described the effect: "“It doesn’t distort colors too tremendously bad…. I think the biggest distortion that we see is that it does darken up white, making it look more yellowish. But your reds and blues — even your greens — that are displayed on the instrument panel screen still look red, blue and green.” (The story is also reprinted here at LaserPointerSafety.com.)

The Commercial Aviation Low Intensity (CALI) laser glare protection glasses developed by the Air Force

June 2018 guidance from an aviation advisory committee, SAE Aerospace Recommended Practice 6378, discusses Laser Glare Protection. An appendix lists LGP products known to the SAE G10-OL committee at time of writing the document.

“Eyewear Helps Thwart Laser-Pointer Attacks”, by Jason Palidwar, Iridian Spectral Technologies. Reprinted from Photonics Spectra, January 2014.

The Air Force Aircrew Laser Eye Protection (ALEP) program. This unclassified document describes many of the characteristics of anti-laser glasses used by the Air Force. It does not list specific wavelengths or protection factors (e.g., optical density) as these are classified. From the abstract: “ It describes design criteria used in the development of laser protective devices, operational considerations, training, fit, inspection, maintenance and immediate response procedures to follow after suspected laser exposure. Procedures outlined in this document apply to all Air Force personnel….” Block 0, 0+ and 1 versions are discussed.

ALEP Program Status: Below is the bottom half of slide 4, in an Air Force briefing about Aircrew Performance Programs. This has more information about ALEP Block 2.

Teledyne wins $7.7 million contract for 3,137 ALEP Block 2 spectacles. News item from February 3, 2012.