Doctors do not recommend shining a laser pointer into the eyes, as with prolonged exposure there is a risk of damage to the retina. If you experience discomfort in the area of the organs of vision, you should consult an ophthalmologist. An acute reaction of the body may indicate the course of serious pathological processes in the body and ophthalmic diseases.
Why can't you shine a laser in your eyes?
In everyday life and educational institutions, laser pointers with a power of no more than 5 mW are most often used, which do not pose a high danger to the organs of vision.
The most common red electronic devices are those that emit electromagnetic waves in the visible spectrum. Bright light provokes a sharp contraction of the pupils, which is fraught with the temporary appearance of black dots in the field of view and a cloudy visual picture. Long-term exposure to lasers with a power of more than 20 mW causes a thermal burn of the retina, which can provoke irreversible pathological processes in the eyes and damage the retina. The most powerful pointers used in the industry are green and 1-2 watts. It is forbidden to work with such equipment without protective equipment, as it is very dangerous for the eyes. However, in everyday life, it is unlikely to encounter lasers of such power.
Effects of glow in the eyes
If a person's organs of vision are sensitive, then their reaction to such an effect may be lacrimation.
Conventional laser pointers do not harm the organs of vision, unlike industrial ones, the action of which can lead to burns and loss of vision. However, with prolonged exposure and increased photosensitivity, the following unpleasant symptoms may occur.
Sep 17
What happens if a laser beam hits the eye? Or a few words about safety during laser procedures in cosmetology
It was 50 years ago that the laser was used only to remove neoplasms, and even then - on the face and body. Since the advent of devices with more subtle settings, rejuvenating and tattoo removal procedures have begun to affect the areas of the eyebrows, outer corners of the eye, and ciliary edges of the eyelid. But in the same place the eyes are not far away! Is it dangerous or not? What happens if the laser does hit the eye? How to eliminate risks for the patient and the doctor?
Lasers are different
Medical laser systems have 4 hazard classes:
- Class 1 considered incapable of generating damaging levels of radiation during operation. It is safe under all conditions of normal use with the naked eye or magnifying optics. These systems are exempt from any control or other surveillance. An example is lasers used in diagnostic laboratories. Class 1M is considered incapable of producing hazardous exposure conditions during normal operation if the beam is not viewed with magnifying optics.
- Class 2- low power laser systems; they emit light in the visible part of the spectrum (400-700 nm) and are considered safe because the defense mechanisms (our blink reflex) provide protection. An example is the helium-neon laser (laser pointers).
Class 2M - emits light in the visible part of the spectrum. Eye protection is normally provided by involuntary closing of the eyes when looking at them. However, these systems are potentially dangerous when viewed with some optical devices. - Medium Power Laser Systems class 3... They can be dangerous when looking directly at or looking at the specular reflection of the beam. They are not sources of diffuse reflections and are not fire hazardous. An example of a class 3 laser is the Nd: YAG laser used in ophthalmology.
There are 2 subclasses: 3R and 3B. Class 3R. May be hazardous in some direct and specular reflection conditions if the eye is properly focused and stable and the likelihood of actual damage is small. Class 3B. May be hazardous in direct and specular conditions. - Class 4... These are high power systems. They are the most dangerous, can be sources of diffuse reflection, and are fire hazardous. They can also generate hazardous plasma radiation. These are cosmetic lasers: carbon dioxide, neodymium, argon, alexandrite, pulsed dye laser (PDL).
How the laser works
The wavelengths of laser radiation fall within the ultraviolet, visible and infrared ranges of the electromagnetic spectrum.
Almost all cosmetic lasers work on the principle of selective photothermolysis. This means that their laser energy is absorbed by a specific chromophore:
- melanin - for diode, alexandrite, ruby and dye laser (PDL);
- hemoglobin - for neodymium in yttrium-aluminum garnet and PDL;
- water - for erbium and carbon dioxide lasers, while preserving the surrounding tissue.
For the laser to have the desired effect, three basic requirements must be met:
- Wavelength sufficient for a certain depth of penetration.
- Exposure duration (laser pulse width and pulse duration) less than or equal to the thermal relaxation (TRT) of the target.
- Enough energy per unit area (fluence) to cause irreversible damage to the target chromophore.
Laser power, spot size and duration are also important. So, with a larger spot size, less scattering occurs, but deeper tissue penetration.
Although lasers target specific chromophores, the surrounding dispersion and the resulting thermal effect can cause side effects. Thermal damage occurs when sufficient energy is absorbed by a suitable chromophore at a faster rate than the resulting heat can dissipate. While the major tissue chromophores are targeted, other eye structures that are also rich in these chromophores are susceptible to unintentional damage. They can be the retina, which is rich in hemoglobin and melanin, the choroid, which is rich in melanin, the cornea and lens, which contain a lot of liquid.
Features of the eyelid and eyes
When carrying out laser procedures in the area surrounding the eye, the following should be remembered:
- The skin of the eyelids is very thin.
- The eye contains several targets for different laser beams. These are melanin in the retinal epithelium, pigment in the iris, and water, which makes up most of the eyeball.
- The most vulnerable part of the eye is the retina: a laser beam 400-1400 nm long (and especially 700-1400 nm) is focused directly on it using the bulges of the lens and cornea. As a result, the retina receives 105 times more radiation than the cornea.
- There is such a thing as the Bell phenomenon: when the eye is closed, the eyeball naturally rolls upward. Thus, the pigmented iris can enter the laser penetration range and absorb the radiation.
- Pain receptors are very densely located on the cornea. That is, even a slight heat damage to it leads to severe pain.
Light-eyed patients are particularly susceptible to laser injury if the exposure is delivered by a laser targeting melanin. In them, all radiation hits the retina at once, without diminishing when passing through the epithelium of the iris.
How laser damages eye structures
Laser injury to the eye and the possible degree of injury varies depending on the type of laser. So, devices operating on the basis of potassium titanyl phosphate (KTP) or dyes (PDL) have a short length. They are mainly absorbed by the cornea and lead to photocoagulation, i.e. photothermal effect... In this case, enough heat is generated in the eye tissue to denature the proteins. The retinal temperature can rise from 40 to 60 ° C.
Long wavelength lasers - infrared, diode, Nd: YAG. They travel through the cornea to reach the lens and retina. Their effect is photomechanical, less often - the phenomenon of photocoagulation. The photomechanical effect means that an explosive acoustic shock is generated in the tissues, which can lead to the appearance of fragments and even to perforation of individual structures.
For example, clinically the 1064 nm Nd: YAG laser, which causes most laser eye injuries, is capable of causing retinal hemorrhage, vitreous hemorrhage, scarring, preretinal adhesion formation, and retinopathy when radiation is absorbed by the melanin-rich retinal pigment epithelium. Nd: YAG laser can cause significant damage to the eye and surrounding skin compared to shorter wavelength lasers as it can penetrate deeper layers of the skin.
The danger of long wavelength lasers (e.g. 755-795 nm alexandrite and Nd: YAG laser with a wavelength of 1064 nm) is that their beam is not visible to the eye... This distinguishes them from shorter wavelength (eg KTP) lasers.
Erbium: The 2940 nm YAG laser is another ablative laser that can also be used fractionally. It is more efficiently absorbed by water and collagen and causes less thermal damage than a CO2 laser. Complications of these lasers include erythema, hyper- and hypopigmentation of the iris, skin infections, and corneal trauma.
Remote control cat - this "nickname" received this toy among the owners. Indeed, a laser pointer for cats is one of the most favorite pastimes, second only to a fur mouse or a good old bow on a string. A cat chasing an indefatigable light is absolutely happy. And what some somersaults the pet makes, trying to grab the ghostly prey!
Obviously, why cats run after a laser is a great opportunity to satisfy the hunter's instincts: jumping, running, surprise attacks, overcoming obstacles. What cat would refuse such tempting entertainment? Yes, and excess weight is easy to throw off by means of such catch-ups: all muscle groups are involved, the respiratory and cardiovascular systems are strengthened, the musculoskeletal system is supported.
In addition, a laser toy for cats is a unique way to overcome stress, relieve tension. Having actively run in the evening, the pet sleeps better at night. With this fun, you can even train a cat by learning some simple tricks. And the owner is comfortable - you relax in front of the TV, while entertaining the pet. And the automatic laser does not require the presence of a person at all: if you press the button before leaving for work, the cat is having fun with the time allotted by the timer.
However, like any toy, the laser can be dangerous for cats. First of all, it must be remembered that the ray should not fall on the retina of the eyes, even reflected from a mirror or glossy furniture surface. And the more powerful the laser, the faster it destroys the retina. Therefore, a laser pointer must be purchased from a pet store - lasers higher than 30 mW cannot be used to play with cats.
It is believed that the green color of the beam is safer than the red one. However, only the power affects the degree of danger. But if you choose between red and green laser, it is better to choose green - most cats see the green beam more clearly, even in daylight.
But even a low-power laser pointer for cats, if handled carelessly, can cause injury. The most "harmless" consequences are shallow wounds and bruises received during the next somersault. Much worse than playing with the windows open is one careless movement of the hand, and the cat jumps out the window, rushing after the elusive light. By the way, children's toys are often equipped with lasers (for example, cars and machine guns), so there should be a mosquito net on the windows, otherwise a child passing by may inadvertently attract a hunter.
And the most unobvious minus is chronic dissatisfaction and self-doubt. A laser toy for cats is pure hunting, which means there must be prey. If every time the hunt ends in nothing, the cat begins to doubt its ability to get food, and this is inevitable stress. To avoid feelings of dissatisfaction, at the end of the game, the cat should receive a "mouse". You can aim the laser at, turning it off when the hunter pokes her nose into the find. Or transfer the beam to another toy that the pet likes to carry in its teeth. If the cat appreciates attention, the laser is moved to the legs and turned off, while stroking and praising the running pet.
Laser radiation is narrowly directed forced energy fluxes. It can be continuous, single power, or pulsed, where the power periodically reaches a certain peak. Energy is generated using a quantum generator - a laser. The flow of energy is electromagnetic waves that travel in parallel with each other. This creates a minimum scattering angle and a certain precise directivity.
Scope of laser radiation
The properties of laser radiation allow it to be used in various spheres of human life:
- science - research, experimentation, experimentation, discovery;
- military defense industry and space navigation;
- industrial and technical sphere;
- local heat treatment - welding, cutting, engraving, brazing;
- home use - laser sensors for barcode reading, CD-ROM readers, pointers;
- laser spraying to increase the wear resistance of the metal;
- creation of holograms;
- improvement of optical devices;
- chemical industry - triggering and analyzing reactions.
The use of laser in medicine
Laser radiation in medicine is a breakthrough in the treatment of patients requiring surgery. The laser is used for the production of surgical instruments.
The undeniable advantages of surgical treatment with a laser scalpel are obvious. It allows you to make a bloodless soft tissue incision. This is ensured by instant soldering of small vessels and capillaries. During the use of such an instrument, the surgeon fully sees the entire operating field. The laser energy stream cuts at a certain distance, without contacting the internal organs and blood vessels.
Ensuring absolute sterility is an important priority. The strict directionality of the beams allows operations to be performed with minimal trauma. The rehabilitation period for patients is significantly reduced. A person's ability to work returns faster. A distinctive feature of the use of a laser scalpel is painlessness in the postoperative period.
The development of laser technologies has made it possible to expand the possibilities of its application. The properties of laser radiation have been found to have a positive effect on the condition of the skin. Therefore, it is actively used in cosmetology and dermatology.
Depending on its type, human skin absorbs and reacts to rays in different ways. Laser devices can create the desired wavelength in each case.
Application:
- epilation - destruction of the hair follicle and hair removal;
- acne treatment;
- removal of pigment and birthmarks;
- skin resurfacing;
- application for bacterial damage to the epidermis (disinfects, kills pathogenic microflora), laser radiation prevents the spread of infection.
Ophthalmology was the first industry to use laser radiation. Directions in the use of lasers in eye microsurgery:
- laser coagulation - the use of thermal properties for the treatment of vascular diseases of the eye (damage to the vessels of the cornea, retina);
- photodestruction - tissue dissection at the peak of laser power (secondary cataract and its dissection);
- photoevaporation - prolonged exposure to heat, used in inflammatory processes of the optic nerve, with conjunctivitis;
- photoablation - gradual removal of tissues, used to treat dystrophic changes in the cornea, eliminates its opacity, surgical treatment of glaucoma;
- laser stimulation - has an anti-inflammatory, absorbent effect, improves eye trophism, is used to treat scleritis, exudation in the eye chamber, hemophthalms.
Laser irradiation is used for skin cancer. The most effective laser is for melanoblastoma removal. Sometimes the method is used to treat stage 1-2 cancer of the esophagus or rectum. With a deep tumor and metastases, the laser is not effective.
What is the danger of a laser to humans
The effect of laser radiation on the human body can be negative. Irradiation can be direct, diffuse and reflected. The negative impact is provided by the light and thermal properties of the rays. The degree of damage depends on several factors - the length of the electromagnetic wave, the location of the impact, the absorbency of tissues.
The eyes are most susceptible to laser energy. The retina of the eye is very sensitive, so it often burns. The consequences are partial loss of vision, irreversible blindness. The source of laser radiation is infrared devices, emitters of visible light.
Symptoms of laser damage to the iris, retina, cornea, lens:
- soreness and cramps in the eye;
- swelling of the eyelids;
- hemorrhage;
- cataract.
With medium-intensity radiation, thermal burns of the skin occur. The temperature rises sharply at the point of contact between the laser and the skin. Boiling and evaporation of intracellular and interstitial fluid occurs. The skin turns red. Under pressure, tissue structures rupture. Edema appears on the skin, in some cases intradermal hemorrhage. Subsequently, necrotic (dead) areas appear at the site of the burn. In severe cases, skin charring occurs instantly.
A distinctive feature of a laser burn is the clear boundaries of the skin lesion, and bubbles form in the epidermis, and not under it.
With diffuse skin lesions at the site of the lesion, it becomes insensitive, and erythema appears after a few days.
Infrared laser radiation can penetrate deeply through tissues and affect internal organs. A characteristic of a deep burn is the alternation of healthy and damaged tissue. Initially, when exposed to rays, a person does not experience pain. The most vulnerable organ is the liver.
The effect of radiation on the body as a whole causes functional disorders of the central nervous system and cardiovascular activity.
Signs:
- drops in blood pressure;
- excessive sweating;
- unexplained general fatigue;
- irritability.
Laser Precautions and Precautions
The most at risk of radiation exposure are people whose activities are associated with the use of quantum generators.
In accordance with sanitary standards, laser radiation is divided into four hazard classes. For the human body, the danger is posed by the second, third, fourth classes.
Technical methods of protection against laser radiation:
- Correct layout of industrial premises, interior decoration must comply with safety regulations (laser beams must not be mirrored).
- Appropriate placement of emitting installations.
- Fencing the area of possible exposure.
- The order and observance of the rules of maintenance and operation of equipment.
Another laser protection is individual. It includes such means: goggles against laser radiation, protective covers and screens, a set of overalls (technological gowns and gloves), lenses and prisms, reflecting beams. All employees must undergo regular preventive medical examinations.
The use of a laser in everyday life can also be hazardous to health. Improper use of light pointers, laser flashlights can cause irreparable harm to humans. Laser protection provides simple rules:
- Do not direct the radiation source at glasses and mirrors.
- It is strictly forbidden to direct the laser into the eyes of yourself or another person.
- Keep laser gadgets out of the reach of children.
The action of the laser, depending on the modification of the emitter, is thermal, energy, photochemical and mechanical. The most dangerous is a laser with direct radiation, with high intensity, narrow and limited beam directivity, high radiation density. Dangerous factors that contribute to radiation exposure include high operating voltage in the network, air pollution with chemicals, intense noise, X-rays. The biological effects of laser radiation are divided into primary (local burn) and secondary (non-specific changes as a response of the whole organism). It should be remembered that the thoughtless use of homemade lasers, light pointers, lamps, laser flashlights can cause irreparable harm to others.
Perfectly smooth skin. Only in advertising does a woman shave, remove and pull out hairs with a smile on her face, because she knows for sure that you can forget about unnecessary vegetation for months. In reality, no procedure gives a long-term effect. None, except for laser hair removal. But is it worth throwing out all the shaving razors and making an appointment with a beautician? Is there any harm from laser hair removal or did marketers specifically spread this myth? Let's figure it out.
Three questions about the need for laser hair removal
Remember how you get rid of unnecessary and overgrown grass. It is burned out, after which it does not grow for a long time. The principle of laser hair removal is very similar to this example. A beam of different-frequency thermal and light directivity, like a magnet, is attracted to the hair follicle, and splits it. Literally it burns out.
In this regard, the question arises - is it safe for the body?
Question 1. Can you live without hair?
Have you ever wondered why we need hair? It is unlikely to spoil the aesthetics and add problems.
Body hair plays a role in thermoregulation. Note that in cold weather they retain heat, and in hot weather they help remove moisture from the body and cool the skin. In summer, hairs on the arms and legs can also act as a protective barrier against small insects.
What about intimate and underarm hair? Their absence, on the contrary, prevents the accumulation of unpleasant odors and bacteria. So smooth skin is good for your health?
Scientists have proven that it is the glands located in these areas that, when heated, emit a smell that can attract the opposite sex. This does not mean that now you can not wash for weeks and seduce men with a natural body scent. But clean skin, warmed by hairs, will be a good substitute for perfume with pheromones.
Given these properties, does it make sense to remove hair completely and permanently?
Question 2. The body's response to the lack of hair
The second question is inextricably linked with the first. If hair is not a useless consequence of evolution, how will the body react to its absence?
You've probably noticed that a side effect of taking hormones is weight gain and hair growth. The absence of hair along with follicles acts in the same direction. The body, trying to restore its usual state, begins to produce an excess amount of hormones.
Hair can start growing in unexpected places
arrow_left Hair can start growing in unexpected places
The result can be not only the time spent on laser hair removal, but also menstrual irregularities and the appearance of excess weight. People with hormonal imbalance need to seriously think about the possible consequences of the procedure.
Question 3. Is the laser so safe?
Modern medicine has gone far ahead. The laser is used to restore vision, carry out major surgeries, and even remove scars and unwanted tattoos. Maybe laser hair removal, on the contrary, is useful?
The use of a laser during surgery comes down to one thing - preventing blood loss. Laser hair removal does not pursue such goals. In addition, when talking about the miraculous properties of the laser, no one mentions that it is contraindicated in oncology. Any radiation can provoke further tumor growth.
Contraindications to the procedure
If you understand that the lack of body hair is not a problem, but its solution, and stories about hormonal disruption will not scare you, then make sure that there are no obstacles on the way to smooth skin.
Consult your doctor if you can undergo laser hair removal if you have:
Infectious and colds. Laser hair removal can provoke the spread of infection throughout the body. Cold treatment will drag on for several more days. It is especially necessary to be careful during an exacerbation of herpes. During this period, it is better to completely abandon any beauty procedures.
Allergy. The reaction to laser hair removal is unpredictable. It is possible that the body's response will be rashes, swelling and itching. Coupled with an already existing allergy, it can come to Quincke's edema.
Phlebeurysm. Laser hair removal has a negative effect on thinned veins, injures blood vessels and provokes damage to capillaries. There is also an opinion that any hair pulling can lead to the development of varicose veins.
Skin conditions like eczema and psoriasis. Laser hair removal is completely contraindicated during an exacerbation of the disease.
Diabetes. With diabetes mellitus, tissue regeneration is impaired, which means that epilation can seriously damage the skin.
Pregnancy and lactation. The body's response to laser exposure during pregnancy has not been studied. This means that there is no unequivocal opinion of doctors whether it is possible to get rid of unwanted vegetation in this way or not. It is better to abstain for several months and think about less effective, but safe methods.
Completely contraindicated
Laser hair removal is completely contraindicated in the following diseases:
- oncology
- herpes
- diabetes mellitus of some forms and types
Laser hair removal should also be discarded if you have an individual intolerance.
Only dark hair is a target for the laser, so if you have very light or gray hairs on your body, you should not do epilation. The harmful effect will not be observed, just like the beneficial one.
Destruction of myths
There is some good news as well. Some speculations about the dangers of laser hair removal are far-fetched.
Myth 1. No tanning before epilation
There is a lot of controversy about the benefits and dangers of tanning, especially if it is obtained artificially. If you were just about to go sunbathing, then read - this is true or fiction.
Tanned skin cannot affect the hair removal procedure. The myth goes back to the days when laser hair removal was just beginning its formation, using the principle of selective photothermolysis. And it did have a detrimental effect on tanned skin. Modern technologies make it possible not to pay attention to this.
Myth 2. Internal organs are damaged
Forget scary stories about internal organ damage or radiation exposure during the procedure. The spectrum of the beam is so small that it will not go anywhere beyond the hair follicle. This means it will not penetrate the skin.
Myth 3. Provoking oncology
Hair removal, even this radical, cannot provoke cancer. This requires a whole range of conditions. But it is quite possible to develop a maturing malignant formation. But radio frequency devices, junk food and even the habit of biting your lips have such a feature.
Undoubtedly, before the procedure, it is necessary to consult with a specialist and undergo an examination.
Myth 4. Provoking skin burns
The laser does not burn out the skin itself, but the hair follicle, splitting the main coloring substance - melanin. The rest of the skin has an insignificant amount of it, and therefore the laser does not see them. Even if you feel warm during the procedure, it will not be enough to burn your skin.
The consequences of shugaring, which is considered less dangerous
arrow_left The consequences of shugaring, which is considered less dangerous
Myth 5. Ingrown hairs and scars form
With home hair removal, such a nuisance is no exception, since the epidermis is injured. The laser acts on the hair itself without disturbing the structure of the skin, which means it eliminates the problem of ingrowth.
Conclusion
Before any cosmetic procedure, you should consult your doctor for advice. To establish the sensitivity of the skin to the laser, the absence of allergic reactions, oncological and dermatological diseases. Taking these features into account will help you to abandon the procedure for medical reasons or to pamper yourself with smooth skin without harm to your health.
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