ልዑል ሓይሊ ዘለዎ ሌዘር ዓይኒ ምውቃዕን ኣኮስቲክ ምዝንባዕ መከላኸሊን።¶

ልዑል ሓይሊ ዘለዎም ብኢድ ዝእሰሩ ሌዘር (ክላስ 3Bን ክላስ 4ን ሰማያዊ፣ ቀጠልያን ቫዮሌትን ሌዘር ካብ 500 ክሳብ 5,000+ ሚሊዋት ዝተዋህለለ ብርሃናዊ ሓይሊ ዝፍንዉ፣ እዚ ድማ ክሳብ 1,000 ዕጽፊ ናይቲ ሕጋዊ 5-ሚሊዋት ገደብ ንመደበኛ ኣቀራርባ ጠቋሚ) ከምኡ’ውን ልዑል ጽዓት ዘለዎም ኣንፈታዊ ኣኮስቲክ መሳርሒታት (ከም Long Range Acoustic Devices ወይ... LRADs፣ ልዑል ደሲቤል ዘለዎም ናይ ተሽከርከርቲ ድምጺ መዳፍዕን ኢንዱስትርያዊ ኣልትራሶኒክ/ኣኮስቲክ ሳይረንን) ብንግዳውን ሓፈሻውን ፓይለታት ኣቬሽን፣ መራሕቲ ጽርግያታት፣ ኦፕሬተራት ባቡር፣ ሰራሕተኛታት ባሕሪ፣ ጋዜጠኛታትን ኣብ ጥቓ ዞባታት ምቁጽጻር ህዝቢ ብዝተታሕዙ ሲቪላትን ዝያዳ የጋጥሞም ኣሎ። ሓደ ዝተዋህለለ ጩራ ሌዘር ብለይቲ ንመስትያት መኪና፡ ንመሸፈኒ ኮክፒት ነፋሪት ወይ ዓይኒ ሰብ ክሃርም ከሎ፡ እቲ ንእሽቶ ምዕራባዊ ጩራ ኣብቲ ብርጭቆ ዝርከቡ ማይክሮ-ስክራችታት ብምስጋር ተበላሽዩ ናብ ሓደ ንብምሉኡ ካቢን ዝመልእ ዕዉር ኒዮን ብርሃን ይፈንጅር፡ እዚ ድማ ብቕጽበት ፍላሽ ዕውርነት ይፈጥርን ኣብ ማኩላ ቀዋሚ ማይክሮስኮፒካዊ ነዃል ከቃጽልን ይኽእል። (fovea) ናይ ረቲና ኣብ ትሕቲ 0.25 ካልኢት።

ብተመሳሳሊ መንገዲ፡ ካብ 135 ክሳብ 160 ደሲቤል (dB) ዝበጽሕ ጽኑዕ ትኹረት ዝገበረ 2,000 ክሳብ 4,000 ሄርትዝ ጸቕጢ ድምጺ ዝፍንው ኣንፈታዊ ድምጺ ምዝንባዕ ጩራ ምቅላዕ፡ ብርቱዕ ቃንዛ ውሽጣዊ እዝኒ፡ ምብታኽ ከበሮ እዝኒ (ቲምፓኒክ ሽፋን)፡ ቀዋሚ ምጉዳል ስሚዒት ሴንሶሪነራል፡ ከምኡ’ውን ጽዑቕ ቬስቲቡላር ቨርቲጎ የበግስ (ረስኒን ሚዛን ምጥፋእን)። ካብ ኣንፈት ዘለዎ ብርሃናዊ ወይ ድምጺ ምውቃዕ ንምድሓን ቅጽበታዊ ኣካላዊ መከላኸሊ ሪፍለክስ የድሊ: ንርሑቕ ምጥማትን መንኵብካ ብድሕሪ ዘይግሉጽ ዳሽቦርድ ወይ ዓንዲ ምውዳቕ (ነቲ ተኳሲ ንምርካብ ናብቲ ምንጪ ጩራ ገጽካ ፈጺምካ ምጥማት)፣ ናብ ውሑስ ደው መበሊ እናተጓዓዝካ ፋሕፋሕ መስትያት ንፋስ ብሓንቲ ኢድ ወይ ብመከላኸሊ ጸሓይ ምዕጋት፣ ካብቲ ጸቢብ 15 ክሳብ 30 ዲግሪ ዝበጽሕ ጸቢብ ውዕል ብጎኒ ምውጻእ ኣኮስቲክ ኤሚተር ኣብ እዋን ምዕሻግ ንመተሓላለፊ እዝኒ፡ ከምኡ’ውን ማእከላይ ዕዉር ነጥቢ (ስኮቶማ) እንተቐጺሉ ኣብ ተመሳሳሊ መዓልቲ ህጹጽ መርመራ ዓይኒ ረቲና ምርካብ።

እዚ ሕጂ ግበሩ¶

ኣብዚ ሕጂ እዋን ድሙቕ ቀጠልያ፡ ሰማያዊ፡ ቫዮሌት ወይ ቀይሕ ጩራ ሌዘር ኣብ ኣዒንትኻ፡ ኣብ መስትያት ተሽከርካሪት ወይ ኣብ ኮክፒት ነፋሪት እንተሃሪሙ፡ ወይ ድማ ብዝወግእ ልዑል ደሲቤል ዘለዎ ኣንፈታዊ ኣኮስቲክ ጩራ እንተተሃሪምካ፡ ነዞም ሽዱሽተ ስጉምትታት ብኡንብኡ ፈጽሞም፤

1. ብቕጽበት ኣንቃዕሪርካ ገጽካ ኣርሕቕ፡ ናብ ምንጪ ጩራ ሌዘር ገጹ ድማ ፈጺምካ ኣይትጠምት: ነቲ ተፈጥሮኣዊ ናይ ሰብ ስንባደ ሪፍለክስ ምግልባጥ ብቐጥታ ኣብ ጸልማት ንዝፍጠር ሃንደበታዊ ድሙቕ ብልጭታ ምጥማት። ብቐጥታ ናብ ትሕቲ ኣክሲስ ናይ ሓደ ልዑል ሓይሊ ዘለዎ ክላስ 4 ሌዘር ምጥማት ነቲ ውሁድ ብርሃን ብመነጽር ዓይንኻ ብ100,000 ረቛሒ ብቐጥታ ናብ ማእከላይ ፎቭያ ረቲናኻ የተኩሮ፣ እዚ ድማ ሽፋን ዓይንኻ ዋላ ምብራህ ከይተረፈ ምውዳኡ (0.25 ካልኢት) ቅጽበታዊ ተርማል ቃጸሎ ረቲና የስዕብ። መንኵብካ ኣውዲቕካ፡ ደጋጊምካ ኣዒንትኻ ኣንቃዕሪርካ፡ ኣዒንትኻ ናብ መሳርሒታት ዳሽቦርድካ ወይ ናብ የማናይ ወሰን መስመርካ ኣቕንዕ።
2. If driving or flying, hold up one open hand or flip down the sun visor to block windshield glare and maintain control: When a laser hits a dusty or scratched car windshield or cockpit canopy at night, the glass lights up like a solid neon wall (veiling glare). Keep your head steady, raise one hand (or flip down the overhead sun visor) to block the bright point on the glass, look underneath or around the glare at the white pavement fog line (or cockpit instrument panel), switch on your four-way hazard flashers, and brake smoothly without swerving.
3. Never rub your eyes after a laser strike: Rubbing a dazzled or flash-blinded eye increases intraocular pressure and irritates the cornea without helping the bleached photoreceptor pigments (rhodopsin) recover. Blink naturally in dim lighting and wait 30 seconds to 5 minutes for your dark-adapted retinal cones and rods to regenerate.
4. If hit by a high-decibel acoustic weapon (LRAD) or sound cannon, step LATERALLY (sideways) behind a solid wall or vehicle while plugging your ear canals: Directional acoustic arrays fire a narrow, spotlight-like sound beam (typically a 15-to-30-degree cone straight ahead of the flat rectangular dish). Running straight backward away from the emitter keeps you inside the pain beam for 100 meters (330 feet); instead, press the fleshy flaps of your ears (the tragus) firmly inward with both index fingers to seal your ear canals, open your mouth slightly to equalize eardrum pressure, and sprint 90 degrees sideways (perpendicular to the dish) behind a concrete building corner, brick wall, or large truck.
5. Go to an Emergency Department or Ophthalmologist the same day if a dark spot, blurred center vision, or red/black floaters remain after 15 minutes: Temporary afterimages (similar to a camera flash) normally fade within 2 to 15 minutes. If you still see a central dark smudge or missing letters when reading with one eye covered (central scotoma), wavy straight lines (metamorphopsia), or floating dark cobwebs (vitreous or retinal hemorrhage), go to an ophthalmologist or hospital eye emergency clinic within hours for optical coherence tomography (OCT) and high-dose corticosteroid evaluation.
6. Report the exact location and beam color of any vehicle or aircraft laser strike to police and aviation authorities: Once stopped safely or after handing controls to a non-dazzled co-pilot, call your local emergency number (911 in the United States and Canada, 112 across the European Union, 999 in the United Kingdom) or check our ናይ ህጹጽ እዋን ቁጽሪ directory (and Air Traffic Control if flying). Aiming a laser at an aircraft or moving vehicle is a serious felony in nearly every jurisdiction; reporting the beam color and street intersection allows police helicopters and patrol units to locate the perpetrator immediately.

ሌዘር ዓይኒ ምውቃዕን ኣኮስቲክ ምዝንባዕን ታክቲካዊ ውሳነ ፍሎውቻርት¶

ነዚ ናይ ውሳነ ገረብ ኣብ እዋን ቀጥታዊ ብርሃናዊ ወይ ድምጺ ፍጻመ ንምርኣይ፡ ምስማዕካን ንመቆጻጸሪ ተሽከርካሪትካን ንምሕላው ተጠቐመሉ።

flowchart TD
    Event["ኣንፈት ዘለዎ ፍጻመ ጸዓት፡ ሃንደበታዊ ድሙቕ ጩራ ሌዘር ወይ ምውጋእ ልዑል-ዴሲቤል ኣኮስቲክ ማዕበል"] --> Modality{"1. ኣየናይ ዓይነት ሓደጋ እዩ ዝሃርመካ ዘሎ?"}
    Modality -->|"ሀ.ልዑል ሓይሊ ዘለዎ ጩራ ሌዘር (ቀጠልያ፣ ሰማያዊ፣ ቫዮሌት ወይ ቀይሕ)"| ContextCheck{"2. መኪና/ነፋሪት ዲኻ ትሰርሕ ዘለኻ ወይስ ብእግሪ?"}
    Modality -->|"B. ልዑል ደሲቤል ዘለዎ ኣኮስቲክ ጩራ (LRAD ድምጺ መዳፍዕ / ኣልትራሶኒክ ሳይረን)"| SealEars["ትራጉስ ፍላፕስ ንውሽጢ ብምጽቃጥ ንካናላት እዝኒ ምዕጻው፤ ጸቕጢ ከበሮ እዝኒ ንምምዕርራይ ቁሩብ ኣፍ ክፈት"]
    ContextCheck -->|"መኪና፡ ናይ ጽዕነት መኪና ወይ ባቡር ምዝዋር"| DriveShield["ናብ ምንጪ ጩራ ቁሊሕ ኣይትበሉ፤ ፍሊፕ ዳውን ሳን ቫይዘር ወይ ብሎክ ግሌር ስፖት ብሓንቲ ኢድ፤ ዳሽ መብራህቲ ንላዕሊ ምጥዋይ"]
    ContextCheck -->|"ፓይሎት ነፈርቲ"| PilotShield["ዋልታ ዓይኒ፤ ቁጽጽር ናብ ዘይተቓልዐ ፓይሎት ምትሕልላፍ ('ነፋሪት ኣለካ')፤ መብራህቲ ኮክፒት ንላዕሊ ምጥዋይ፤ ንኤቲሲ ደውሉ።"]
    ContextCheck -->|"ኣብ እግሪ / ህዝቢ / ናይ ስራሕ ቦታ"| FootShield["ርእሲ 90 ዲግሪ ርሒቑ፤ ድሮፕ ቺን፤ ዋልታ ዓይኒ ብኢድ ወይ ቆቢዕ ጫፍ፤ ድሕሪ ዘይግሉጽ ሽፋን ምግዓዝ"]
    DriveShield --> SafeStop["የማናይ መስመር ዕንበባ ብምጥቃም ምዝዋር፤ ናይ ሓደጋ ፍላሸራት ምውላዕ፤ ካብ መንገዲ ብውሑስ መንገዲ ስሓብ፤ ናብ 911 / 112 / 999 ጸብጻብ"]
    PilotShield --> VisionCheck{"3. ኣብ ንቡር ብርሃን ካብ 10 ክሳብ 15 ደቓይቕ ድሕሪ ምጽናሕ፡ ምርኣይካ ከመይ ኣሎ (ሓንቲ ዓይኒ ኣብ ሓደ እዋን መርመራ)?"}
    FootShield --> VisionCheck
    SafeStop --> VisionCheck
    VisionCheck -->|"Afterimage ምሉእ ብምሉእ ይሃስስ & ንባብ ራእይ ርሱን እዩ።"| Monitor24["ዓይኒ ኣይትሕከኽ፤ ዕረፍቲ ዓይኒ፤ መደብ ስሩዕ መርመራ ዓይኒ ቅልል ዝበለ ቃንዛ ዓይኒ እንተቐጺሉ ምፍታሽ"]
    VisionCheck -->|"ኣብ ማእከላይ ምርኣይ፡ ማዕበል መስመራት፡ ፍሎተር ወይ ቃንዛ ዓይኒ ቀጻሊ ጸሊም ነጥቢ"| UrgentEye["ህጹጽ ሕክምና: ናብ ሓኪም ዓይኒ / ዓይኒ ER ኣብ ተመሳሳሊ መዓልቲ ንRetinal OCT Scan & Steroid Triage ኪድ"]
    SealEars --> MoveLateral["ብድሕሪ ጽኑዕ ኮንክሪት/መሸፈኒ ተሽከርካሪት 90 ዲግሪ ብጎኒ (ካብቲ 30 ዲግሪ ድምጺ ኮን ብጎኒ ወጺእካ) ኣንቀሳቕስ"]
    MoveLateral --> EarCheck["ምፍሳስ ደም እዝኒ፡ ከቢድ ምውጥዋጥ ወይ ምዕባስ ምስማዕ እንተቐጺሉ: ኣብ ውሽጢ 24 ሰዓታት ንሓኪም ENT / ህጹጽ ረድኤት ርአ"]

ምርዳእ ናይ ሌዘር ዓይኒ መጉዳእቲ፡ ዳዝል ኣንጻር ፍላሽ ብላይንድነስ ኣንጻር ቀዋሚ ረቲናል በርን¶

ጩራ ሌዘር ናብ ዕንፍሩር ዓይንኻ ምስ ዝኣቱ፡ ኮርኒያን ክሪስታላዊ መነጽርን ነቲ ምዕራባዊ ጩራ ኣብ ረቲና (ኣብ ድሕሪት ዓይንኻ ዝርከብ ንብርሃን ዝስምዖ ኒውራል ቲሹ) ኣብ ዝርከብ ማይክሮስኮፒካዊ ቦታ የተኩርዎ፡ እዚ ድማ ነቲ ጽቕጥቕጥ ጸዓት (ጨረርታ) ክሳብ 100,000 ዕጽፊ የተኩርዎ። ብመሰረት ምምሕዳር ፈደራላዊ ኣቬሽን (FAA, ሕቡራት መንግስታት ኣመሪካ)፡ ኣህጉራዊ ውድብ ሲቪላዊ ኣቬሽን (ICAO)ን ኣመሪካዊ ኣካዳሚ ሕክምና ዓይኒ (AAO)፡ ምቅላዕ ሌዘር ሰለስተ እናወሰኸ ዝኸይድ ደረጃታት ምዝንባዕ ምርኣይ የስዕብ፤

Exact survival protocols for drivers and pilots hit by a laser at night¶

Protocol A: For Motorists, Truck Drivers, and Train Operators¶

Criminals and vandals standing on highway overpasses, pedestrian bridges, or roadside embankments occasionally shine high-powered green or blue lasers into the windshields of oncoming cars and semi-trucks at night.

1. Keep your eyes glued to the right-hand white pavement edge line (Fog Line): Just as when blinded by oncoming high-beam headlights, immediately shift your focal point downward and to the right (or left in left-hand-drive countries like the UK and Australia) to track the solid white painted edge line of your lane right in front of your hood.
2. Flip down your Sun Visor and turn your interior dashboard / dome light UP:
3. Flipping the opaque sun visor down blocks laser beams aimed from highway overpasses or hillsides above your car.
4. Turning up your dashboard instrument brightness (or briefly clicking on the map light) slightly constricts your dark-adapted pupils from 7 millimeters down to 3 millimeters and reduces the contrast shock of the laser flash.
5. Never slam on the brakes in the middle of a high-speed highway lane: Braking hard to a dead stop in a live freeway lane while dazzled causes fatal rear-end chain collisions from trailing traffic whose drivers may also be dazzled by the same laser. Switch on your four-way hazard flashers, ease your foot off the accelerator, hold the steering wheel straight, and coast onto the right shoulder only when you can see the pavement edge clearly.
6. How to check if your windshield is magnifying the glare: Dirty windshields covered in interior smoker's film, dashboard plastic off-gassing haze, or exterior road salt scatter laser light 10 times worse than clean glass. Do not turn on your windshield washer spray while the laser is hitting the glass, because water droplets on the glass act as thousands of tiny convex lenses that scatter the laser beam across the entire windshield.

Protocol B: For Commercial, Helicopter, and General Aviation Pilots¶

Laser illumination of aircraft during night takeoff and final approach exceeds 10,000 reported incidents annually in the United States and Europe alone. FAA Advisory Circular AC 70-2B and ICAO aviation medicine standards prescribe this exact cockpit sequence:

1. Protect Your Eyes First ("Look Inside the Cockpit"): The instant a laser flash hits the windscreen, look down inside the cockpit at the instrument panel, and never look out the side window toward the ground to try to pinpoint what backyard the beam is coming from.
2. Block the Windscreen and Turn Cockpit Lights to Maximum: Hold up a clipboard, checklist card, or flare shield to block the illuminated windscreen panel, and turn cockpit dome and flood lights UP to high to eliminate dark-adaptation contrast and minimize veiling glare.
3. Transfer Aircraft Control Immediately if One Pilot Is Dazzled:
4. In a two-pilot crew, if the Pilot Flying (PF) is struck in the eyes and experiences flash blindness, immediately execute a positive transfer of controls ("You have the flight controls" / "I have the flight controls") to the unexposed pilot.
5. In single-pilot aircraft, engage the Autopilot immediately (or fly solely on flight instruments), and execute a missed approach / go-around or gentle climbing turn away from the beam path if illuminated below 300 meters (1,000 feet) AGL on final approach.
6. Report to Air Traffic Control (ATC) Using the Standard Phraseology:
7. Broadcast on your active ATC frequency: "UNAUTHORIZED LASER ILLUMINATION" followed by your position/altitude, beam color, direction/clock position of the source, and whether the beam is tracking the aircraft.

Wavelength-Specific Laser Protection Eyewear (Laser Glare Shields)¶

For commercial pilots, law enforcement helicopter crews, security personnel, and journalists operating in environments where handheld lasers are regularly deployed, ordinary dark sunglasses DO NOT protect the retina from a Class 3B or Class 4 laser:

• Why standard polarized sunglasses fail: Dark tinted sunglasses block only 70 to 85 percent of visible light (Optical Density or OD of roughly 0.5 to 0.8) while causing your pupils to dilate wider in the dark, allowing a 1,000-milliwatt laser beam to pass right through the sunglass lens and burn your retina.
• How Notch-Filter Laser Safety Glasses work: Certified aviation and tactical Laser Eye Protection (LEP) glasses use specialized polycarbonate dyes or thin-film dielectric coatings rated by Optical Density (OD 2+ to OD 4+) at specific laser wavelengths (such as 532 nm green and 445 nm blue). An OD 3.0 filter reduces a dangerous 1,000-milliwatt laser strike by a factor of 1,000 (down to a harmless 1 milliwatt) while allowing non-laser cockpit instrument wavelengths to pass through so you can still read your gauges. Always check that laser eyewear is stamped with the exact protected wavelength range in nanometers (nm) and its ANSI Z136.1 or EN 207 Optical Density rating.

How to perform the 60-Second Self-Test for Retinal Damage (The Amsler Grid Check)¶

If you were struck in the face by a bright laser pointer or handheld laser and want to know whether you have harmless temporary flash blindness or an acute retinal burn that needs an emergency ophthalmologist, wait 10 to 15 minutes in a normally lit room and perform this simple monocular test:

1. Test ONE EYE AT A TIME (Important Rule): Put on your normal reading glasses if you wear them. Cover your left eye completely with the palm of your left hand (without pressing on the eyeball), and look with only your right eye at a page of small printed text, a smartphone keyboard grid, or bathroom wall tile grout lines from 35 centimeters (14 inches) away. Then switch hands and test only your left eye.
2. Why you must cover one eye: Because the human brain automatically uses your healthy eye to "fill in" a small blind spot in your injured eye (binocular suppression), people with a 50-percent macular burn in one eye often do not notice it until they cover their good eye.
3. Check for these four Retinal Emergency Red Flags:
4. A Central Dark, Gray, or Blank Spot (Scotoma): When you stare directly at a single letter in the middle of a word (for example, the "R" in the word SMARTPHONE), does the center letter "R" disappear, look washed out, or sit behind a gray/black smudge while the outer letters ("S" and "E") remain visible?
5. Wavy, Bent, or Distorted Straight Lines (Metamorphopsia): When you look at the straight horizontal and vertical grid lines of a tiled wall, spreadsheet, or doorframe with one eye, do the straight lines bow inward, wave, or kink near the center of your gaze?
6. New Floating Cobwebs, Black Dots, or Red Haze: Do you see new dark spots drifting across your vision or a reddish tint (indicating microscopic bleeding from a ruptured retinal capillary)?
7. Decreased Color Saturation: Does a bright red object look dull brown or faded in the struck eye compared to the uninjured eye?

If any one of these four signs is present 15 minutes after a laser strike, go to a hospital Emergency Department or urgent ophthalmology clinic the same day.

ካብ ሞት ዝደሓኑ ኣኮስቲክ ዲስኦርየንቴሽን ኣጽዋር (LRADs, Sound Cannons, and High-dB Sirens)¶

ኣንፈታዊ ኣኮስቲክ ሃይለርስ፡ ብፍላይ ድማ Long Range Acoustic Device (LRAD)፡ ሶኒክ ክራውድ-ምቁጽጻር መዳፍዕ፡ ከምኡ’ውን ኣዝዩ ልዑል ደሲቤል ዘለዎም ናይ ጸጥታ ሳይረን፡ ብፍሉይ ናብቲ... ካብ 2,000 ክሳብ 4,000 ሄርዝ ሪዞናንት ፍሪኩዌንሲ ናይ ሰብ እዝኒ ካናል።

ኣብ ኣካላት ወዲ ሰብ ኣብ 130 ክሳብ 160 ደሲቤል እንታይ ይኸውን¶

The 4-Step Defense Against an Active Acoustic Beam¶

Because high-frequency acoustic arrays behave like an invisible spotlight of sound rather than an omnidirectional speaker, physics gives you three immediate ways to drop the decibel level by 30 to 40 dB in two seconds:

1. Seal Your Ear Canals Instantly Using the "Tragus Push" (Not Cupped Palms):
2. Putting your flat palms over the outside of your ears blocks only about 5 to 10 dB of high-frequency sound.
3. Instead, place the tips of both index fingers directly onto the tragus (the small, firm cartilaginous flap right in front of your ear hole) and press the tragus flaps firmly inward like built-in biological earplugs to seal the ear canal completely shut. Pressing the tragus inward provides 25 to 30 dB of immediate acoustic attenuation, reducing a painful 145 dB beam down to a survivable 115 dB instantly.
4. If you are carrying foam earplugs (NRR 30 to 33 dB) and/or over-ear shooting/industrial earmuffs, wearing foam earplugs underneath earmuffs ("double protection") blocks up to 35 to 40 dB.
5. Open Your Mouth Slightly and Swallow / Jaw-Wiggle:
6. Just as during an explosion or aircraft descent, keeping your mouth slightly open and moving your jaw opens the Eustachian tubes connecting the back of your throat to your middle ear, allowing acoustic pressure waves to equalize on both sides of your eardrum so the membrane is less likely to tear.
7. Move 90 Degrees LATERALLY (Perpendicular to the Emitter Face):
8. Look at the flat rectangular or circular dish of the LRAD (usually mounted on the roof of an armored vehicle, tripod, or vessel).
9. Because 2.5 kHz sound waves are highly directional, the sound pressure is concentrated in a narrow 15-to-30-degree cone directly in front of the flat face of the emitter.
10. Never run straight backward down the street in front of the dish. Take 10 to 15 fast steps 90 degrees to the left or right to step outside the edge of the sound cone; stepping just 20 degrees off-axis drops the sound intensity by 15 to 25 dB immediately.
11. Put Solid, Dense Mass Between Your Head and the Emitter:
12. High-frequency 2.5 kHz acoustic waves reflect off hard, dense surfaces and cannot easily bend (diffract) around thick corners. Stepping behind a concrete pillar, brick building corner, solid masonry wall, dumpster, or engine block of a car blocks the line-of-sight acoustic wave immediately. (Note: Holding up a cardboard sign, backpack, or umbrella in front of your face does NOT block acoustic waves, and can actually act as a sounding board that vibrates near your head.)

Medical care after an acoustic or ultrasonic injury¶

Once you are away from the sound source in a quiet environment, evaluate your ears and balance:

• Temporary Ringing (Tinnitus) and Muffled Hearing: A high-pitched ringing and a "cotton-stuffed" feeling in the ears (Temporary Threshold Shift) is common for 12 to 48 hours after a loud exposure. Stay in a quiet environment and avoid headphones or loud music for several days to let metabolically exhausted cochlear hair cells recover.
• When to seek same-day ENT / Emergency Medical Care:
• Sudden Sensorineural Hearing Loss (Moderate-to-Severe Deafness in One or Both Ears): Just like retinal burns, acute inner-ear acoustic trauma responds best to early high-dose oral or intratympanic corticosteroid therapy started within 24 to 72 hours of the noise injury to reduce cochlear inflammation and rescue damaged hair cells. Do not wait two weeks hoping muffled hearing will clear up on its own.
• Ruptured Eardrum (Tympanic Membrane Perforation): Indicated by sharp ear pain that suddenly stops, clear fluid or bright blood draining from the ear canal, or a whistling sensation when blowing your nose. Keep the ear 100 percent dry (do not put water, cotton swabs, or over-the-counter ear drops into the ear canal) and see an otolaryngologist (ENT) or emergency doctor.
• Persistent Vertigo or Nystagmus: If the room continues to spin or you cannot walk in a straight line without vomiting more than an hour after leaving the sound zone, seek emergency evaluation for inner-ear perilymph fistula or labyrinthine concussion.

ብተደጋጋሚ ዝሕተቱ ሕቶታት¶

Why shouldn't I look toward the source of a laser beam to see who is shining it at my car or plane?¶

Never look toward the origin of a laser beam, even for a fraction of a second. When you look straight down the path of a laser beam, the lens of your eye focuses the parallel laser light onto the exact center of your macula (the fovea, which provides 100 percent of your sharp reading and driving vision), concentrating the beam's power by 100,000 times. High-powered blue or green lasers sold online can burn a permanent thermal scar onto your fovea in less than 0.25 seconds, which is faster than the human blink reflex. Always look away, drop your chin, and use your peripheral vision or an opaque shield like a sun visor to block the light.

How can I tell if a laser pointer caused permanent damage to my retina or just a temporary afterimage?¶

Wait 10 to 15 minutes in a normally lit room for normal flash blindness (which feels like the glowing spot after looking at a camera flash) to fade, then test your eyes strictly one at a time by covering one eye with your palm and looking at small text or a grid of straight tile lines. If the afterimage fades completely within 15 minutes and letters look sharp and clear in both eyes individually, no permanent burn occurred. However, if you still see a stationary dark or gray smudge blocking the center letter you look at, if straight lines look wavy or bent, or if you see dark floating cobwebs, go to an ophthalmologist or hospital emergency department the same day.

What is the fastest way to escape a painful LRAD sound cannon or directional acoustic beam?¶

First, seal your ear canals immediately by pressing the small cartilaginous flaps at the front of your ears (the tragus) firmly inward with your index fingers like built-in earplugs, and open your mouth slightly to equalize pressure on your eardrums. Second, never run straight backward away from the LRAD dish, because the device projects a narrow 15-to-30-degree spotlight beam of sound straight ahead for hundreds of meters. Instead, run 90 degrees sideways (perpendicular to the face of the emitter) to step out of the directional sound cone and get behind a solid brick wall, building corner, or vehicle.

Should I use my windshield wipers and washer fluid if a laser hits my car windshield at night?¶

No, do not spray windshield washer fluid while a laser beam is hitting your windshield. Wet droplets and streaks across the glass act as thousands of miniature lenses that refract and scatter the laser light across the entire windshield, dramatically worsening the blinding veiling glare inside your car. Instead, leave your wipers off, flip down your overhead sun visor, hold one hand up if needed to block the bright spot on the glass, focus on the right-hand white pavement edge line, and slow down smoothly with your hazard flashers on.

ምንጭታት ተፈቲሾም¶

• Federal Aviation Administration (FAA, United States): Advisory Circular AC 70-2B (Reporting of Laser Illumination of Aircraft), Laser Hazards in Navigable Airspace, and Pilot Medical Countermeasures.
• International Civil Aviation Organization (ICAO) and UK Civil Aviation Authority (CAA, United Kingdom): Manual on Laser Emitters and Flight Safety (Doc 9815) and Cockpit Flash Blindness Recovery Protocols.
• American Academy of Ophthalmology (AAO) and Laser Institute of America (LIA, United States): Diagnosis and Management of Handheld Laser-Induced Maculopathy, Retinal Photothermal Injury, and ANSI Z136.1 Laser Safety Standards.
• National Institute for Occupational Safety and Health (NIOSH / CDC) and OSHA (United States): Criteria for a Recommended Standard: Occupational Noise Exposure, Impulse/High-Decibel Acoustic Trauma, and Dual Hearing Protection.
• American Academy of Otolaryngology, Head and Neck Surgery (AAO-HNS) and Physicians for Human Rights (PHR): Clinical Practice Guideline: Sudden Hearing Loss (Early Corticosteroid Intervention) and Health Impacts of Crowd-Control Acoustic Weapons (LRAD).

ተዛመድቲ መምርሒታት¶

• መጉዳእቲ ዓይኒ፡ ባዕዳዊ ነገራትን ምፍንጫል ኬሚካላትን።
• Rubber bullets, flashbangs, and crowd dispersal injuries
• Civil unrest, protests, and curfews
• Car breakdown and highway shoulder safety
• ጸቕጢ ካቢን ነፋሪት ምጉዳል፡ ኣቀማምጣ ምትእስሳርን ምውጻእን።
• ናይ ህጹጽ እዋን ቁጽርታት ማህደር