What are the effects of lasers on the human body?

In recent years, China's rapid development of the laser industry, the application market is gradually expanding, broke through many problems, unlocked a number of core technologies, and gradually get rid of the foreign "neck" of the predicament. With the booming development of the laser industry, more and more people began to pay attention to the research and development, production and application of lasers. Among them, "what effect will the laser have on the human body?" has become a matter of great concern. In response to this question, Wikipedia will answer for you. 

The effects of lasers on the human body mainly include damage to the eyes and damage to the skin. 

Damage to human skin 

Human skin can form a complete protective layer due to its physiological structure, which will protect the human body in daily life. When a laser with too much power irradiates the skin, it will cause damage to the skin tissue. Although this damage can be repaired by the skin tissue itself, the repaired skin tissue, the protective function will be reduced. 

The degree of laser damage to the skin is mainly affected by the amount of laser irradiation, the wavelength of the laser, the depth of the skin colour and the moisture of the tissue. It has been proved by a large number of experiments that when the laser irradiates the skin, the power density of the laser is positively correlated with the degree of skin tissue damage. The absorption of laser energy by human skin has a certain safety threshold. When the safety threshold is exceeded, the human skin (the part irradiated by the laser) will be erythematous, blistered, carbonised, boiled, burnt or even vaporised due to the increase of laser irradiation. From this, it is easy to know that the damage caused by laser to human skin is mainly due to the thermal effect produced by the laser. 

Damage to the eyes 

When lasers cause damage to the human body, they are most serious to the eyes.

The human eye is an approximate sphere that consists of the wall of the eye, the contents of the eye, and the retina. The wall of the eye consists of three layers of different textures: the cornea and sclera, the iris and choroid, and the retina. The contents of the eye include the crystalline lens, the aqueous chamber, and the vitreous body. 

The refractive system of the eye is made up of the cornea and the contents of the eye, and because of its transparent qualities, light rays are not obstructed as they pass through. The cornea, iris, crystalline lens, vitreous and aqueous humour together form the body's sophisticated optical system for receiving light. 

The refractive system has the characteristics of low absorption, high transmittance and strong focusing ability, which makes the laser enter the eye can pass through the refractive system directly to the retina, at this time, the laser energy density on the retina can be raised thousands or even tens of thousands of times, the retinal temperature is too high leading to necrosis of photoreceptor cells, irreversible damage, or even permanent blindness. 

Far-infrared laser damage to the eye is mainly targeted at the cornea, and ultraviolet laser is mainly absorbed by the crystal. Damage to the cornea will cause keratitis and conjunctivitis, and the injured person will also be accompanied by symptoms such as fear of light, tearing, vision loss and congestion. When the crystal is damaged, it may become cloudy. 

Since the damage to the eyeball caused by laser irradiation is irreversible, it is necessary to attach great importance to the protection of the eye when using it, wear goggles, maintain a certain safety distance, and strictly abide by the relevant rules and regulations in order to avoid the occurrence of injuries fundamentally. 

At present, most of the laser injury cases in China are accidental irradiation accidents, and a few are complications arising from laser treatment. When the human body is injured by laser, it is necessary to take sufficient rest and take protection from light. If the trauma is serious, contact a medical professional immediately, and if necessary, use glucocorticosteroid treatment supplemented by Chinese medicine that activates blood circulation and removes blood stasis. 

Before using the laser for operation, we should check whether there is any light leakage, and seal the position where there may be light leakage; the working environment should be well lit, and the surrounding area should be protected by light-absorbing materials; individuals should check whether the goggles and protective uniforms are intact when they work with lasers. 

All in all, lasers can cause serious harm to the human body, but to a large extent we can avoid it through scientific and standardised means.