In 2004, the U.S. Federal Aviation Administration conducted tests on volunteers to determine how laser exposure affected pilots during the final approach to the runway. The FAA has found that a 5 mW green laser pointer can cause retinal burns at distances of up to 14 meters (50 feet) and short blindness, residual images or glare problems up to 350 meters (nearly a quarter mile). Even at a range of 3 kilometers (2 miles), a green laser pointer can still interfere with a pilot`s vision strongly enough to cause an aborted landing. If you are responsible and avoid such things, everything will be fine. Using a laser for a star party or to show someone the night sky is perfectly acceptable if you take reasonable precautions and use common sense. Looking directly at a laser pointer beam, even briefly at a considerable distance, can lead to temporary blindness of the flash – the same effect you get right after taking a flash photo – or secondary images. These effects last between a few seconds and a few minutes. Glare, a reduction or loss of central vision, lasts only long exposure to the beam.
It is unlikely that a pilot`s or driver`s vision will be damaged by medium-power laser pointers (5 mW to 20 mW), as typical distances are significantly greater than the corresponding NOHD. However, glare caused by the beam that disperses dust or scratches on a windshield, or the flashing reaction itself, can still result in a vehicle losing control. A laser pointer beam can also cause damage in other situations, such as starting someone with a power tool. Laser light from laser pointers can potentially burn the retina of the human eye. The danger is obviously greater when the beam is directed directly into the eye and is not only scattered by the beam and seen from the side. The danger depends on the wavelength of the laser light, the power of the laser pointer, the divergence of the laser beam, the distance of the person from the pointer, whether the beam is seen directly or via reflection, how long the beam is seen, and whether the natural « flashing reaction » of the human eye to bright light occurs. The flashing reaction must protect the human eye at any distance from any laser pointer beam with visible light with a power of less than 1 mW, typical of a Class 2 laser pointer. For more powerful laser pointers, greater distance is required to provide flashing response protection.
For a given laser pointer beam, an amount called a nominal eye danger distance (NOHD) can be calculated. Severe eye damage is likely in NOHD and less likely at greater distances. NoHD depends on the power, wavelength, divergence and diameter of the beam, as well as the duration of viewing the laser pointer beam. For example, a green laser pointer beam (532 nm) of 10 mW, collimated, continuous, with a diameter of 1 mm and a divergence of 10-3 radians, which is directly visualized for 10 seconds, has a NOHD of 55 m. It is clear that this laser pointer, typical of many green laser pointers, presents a potential danger to a loved one and should be used with caution. Theoretically, yes. Except that lasers appear on the market much faster than you can tint all the windows of the plane. (It doesn`t matter who pays for it). So until it`s done a bit, wait for it. There he is. Do not point lasers at night sky lights.
🙂 Point 2 is usually what makes things forbidden because it`s cheaper and easier than prosecuting idiots and holding them accountable for their actions. If you look at the arguments for/against, you see that a) if you ban them, we won`t be able to report astronomical things to a group of people or b) if you don`t ban them, someone will shoot down a plane. It`s a breeze for any politician, especially since deterrents don`t work for real idiots. Please, I`m not advocating a ban, but you can see how it`s going to go, idiots always mess it up for everyone, so if you have a gun and know someone who abuses laser pointers, shoot quickly and you could keep the lasers. But when it hits a mile-high plane, it`s actually visible because you`re looking at a single point that reflects almost all the light from the laser. The hands favored by astronomers use a neodymium diode laser and emit a green beam at a wavelength of 532 nanometers. At a given power setting, these lasers appear much brighter than more common diode lasers, which produce a red beam at wavelengths greater than 630 nm. The reason is simple: the human eye is much more sensitive to green light than to red light. Green laser pointers, common among astronomers and the general public, have a power of just under 5 milliwatts; in the United States, they are called Class 3a lasers. Low-power lasers, such as those used in CD players and laser printers, are Class 1 or 2, while higher power units, such as in medical or industrial devices, are Class 3b or 4.
The higher the class, the stricter the warning label required by the U.S. Food and Drug Administration (FDA). Most laser pointers only turn on as long as you hold down a button. But some models have a « constant » setting. These are becoming increasingly popular as pointing aids for telescopes. Once the laser is mounted and aligned with the bezel, simply move the bezel until it points to your target star, and when you look into the eyepiece, it`s there. I use them with range with kids and they are excellent, funny, safe, legal and we just don`t point them at planes or eyeballs. Laws? What laws? I do not see any laws. We don`t need laws about smelly lasers! If steak knives could be thrown into the cockpits of planes to dazzle pilots responsible for passenger and crew safety, yes. www.fbi.gov/news/stories/2011/september/laser_092611/laser_092611 Here`s a constructive idea.
Make a pointer with a large lens that focuses non-laser light at a distance of 50 m. Will give you a beautiful glimmer of hope and will not hurt anyone. Finally, why green? Our eyes are the most sensitive to green light. The same measured output power of a red laser would not produce a visible beam because our eyes are not as sensitive to red. By the time we could see a red laser, it would likely reach a dangerous level of intensity. So how does my laser work? It works VERY well! Exactly as described – a beam of green light protrudes upwards and stops more or less directly at the object you are pointing at. The end of the bar is a bit more blurry and fades slightly, but it really seems to have an end where the beam essentially stops. It is extremely obvious what you are pointing out. I have not yet tested how far away from me it remains visible, although people who stand six feet away from me can see it without any problems.
What about light pollution? Many websites say that in light-polluted conditions, you will not see the beam and will need more power. I guess it depends on what they mean. When I first used it, I was in a rural area, but not far from the city, and there was a gibbous moon setting. The limit was about 5.0, maybe 5.5. The laser was bright and easy to see.