Laser pointer is the most accessible laser product in our daily life.
It's tiny and simple in appearance, but it emits the brightest light in the world – a laser.
The brightness of the laser light after focusing is tens of millions of times higher than the average brightness of the sun's surface.
Due to the concentrated direction and minimal attenuation, the laser has a small spot but contains a huge amount of energy.
Because of this, the laser has become "an inextinguishable light thousands of miles away".
The small light spot of the laser pointer brings endless fun to children, but it makes the ophthalmologist talk about it.
In recent years, cases of laser pointers hurting the eyes are not uncommon.
The "second killer" of eyesight - laser pointer
urgent
Diagnosis
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example
A few kids compete to see who has their eyes on the laser pointer for a long time. One of the children couldn't even read the largest letter on the eye chart after looking at it for more than 20 seconds.
The results of the examination showed damage to the macular structure in the child's fundus.
Macular is located in the center of the retina and occupies less than 5% of the eye, but controls 90% of vision. The macula determines our sense of light, shape and color.
Laser light can penetrate the intraocular structure to concentrate energy on the macula, and through photochemical and thermal effects, it can cause macular edema, hemorrhage, hiatus, and even cone apoptosis in just a few seconds.
"Precise aiming, rapid blinding" is the danger of laser pointers.
When the macula is "sniped" by a laser, symptoms such as blurred vision, distortion, and color fading may appear, and even dark shadows may appear in front of the eyes.
What's even more terrifying is that the damage caused by laser pointers to vision is irreversible, and the efficacy of drugs and surgeries is not good.
Scientifically select laser pointers
Although for children, laser pointers are dangerous goods that cannot be touched.
However, for teachers, the laser pointer is an infinitely extended whip;
For wilderness explorers, the laser pointer is a cry through the jungle;
For astronomy enthusiasts, a laser pointer is a finger that touches the starry sky......
Therefore, how to scientifically choose and use laser pointers safely is a science.
According to the relevant national standards, laser pointers are divided into Class 1, Class 1M, Class 2, Class 2M, Class 3R, Class 3B, and Class 4 according to the degree of hazard from low to high.
Non-professional users should not choose Class 3B and Class 4 high-power laser pointers, and it is best to choose products with laser radiation category of Class 3R and below (laser power not more than 5 milliwatts).
When using a laser pointer, care should be taken not to shoot at a crowd. If you notice eye damage caused by a laser pointer, see an eye doctor immediately.
Popular science about the dangers of laser pointers
Then by the way, a few more nagging sentences
in everyday life
How can we take effective eye care?
Try these five methods!
Follow the "20-20-20" rule
After 20 minutes of watching the screen, look up at a distance of 6 meters (20 feet) for at least 20 seconds.
Maintain a correct sitting posture
When using a mobile phone
Try to keep your eyes level with your eyes perpendicular to the phone screen, with your back straight and your upper body relaxed.
When watching a computer
The distance between the eyes and the computer screen should not be less than 50 cm, the gaze of the computer is slightly downward, and the center of the computer screen should be about 10 cm below the eye line of sight. The eye gaze is to be fixed at an angle about 15 degrees below the horizon of the eye.
While watching TV
The eye is more than 3 meters away from the TV screen or 6 times the diagonal length of the TV screen, and the height of the center point of the screen is also slightly lower than the height of the person's eyes when sitting.
Sun protection should also be done for the eyes
When outdoors with strong UV rays, be sure to wear sunglasses that protect against UV rays. Dark-colored sunglasses that do not protect the eyes not only do not protect the eyes, but also dilate the pupils and absorb more ultraviolet rays, which may damage the lens, retina, etc.
Make good use of your smartphone's eye protection features
You can use the built-in "Do Not Disturb Mode", "Screen Time Statistics" and other functions or some apps to monitor and analyze your mobile phone usage and help develop a good habit of taking regular breaks.
An acupuncture point to relieve dry eyes
If you look at the screen for a long time and your eyes feel tired and dry, in addition to blinking your head quickly for 1 minute, you can also press and rub the four white acupoints, clockwise and counterclockwise 20 times each, each time for 2~3 minutes.
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