How do lasers affect the human body?

The main effects of lasers on the human body are damage to the eyes and damage to the skin.

Damage to human skin

Human skin, due to its physiological structure, can form a complete protective layer, which protects the human body in daily life. When a laser with too much power irradiates the skin, it can cause damage to the skin tissue. Although this damage can be repaired by the skin tissue itself, the protective function of the repaired skin tissue 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 skin color, and the moisture of the tissue. A large number of experiments have proved 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, and when it exceeds this safety threshold, the human skin (the part irradiated by laser) will be erythema, blisters, carbonization, boiling, burning and even vaporization due to the increase in the amount of laser irradiation. Therefore, it is not difficult to know that laser damage to human skin is mainly due to the thermal effect produced by the laser.

Although the damage caused by laser irradiation to human skin is not enough to affect the overall functional structure of the skin tissue, but in the daily teaching and use of the process still need to strengthen the protection of human skin, according to the requirements of wearing protective clothing, in order to minimize the laser damage to human skin.

Eye damage

When the laser causes damage to the human body, the damage to the eyes is the most serious.

The human eye is an approximately spherical object consisting of the wall of the eyeball, the contents of the eyeball and the retina. The wall of the eyeball consists of three layers of membranes of different textures: the cornea and sclera, the iris and choroid, and the retina. The contents of the eye include the lens, aqueous humor, and vitreous humor.

The refractive system of the eye consists of the cornea and ocular contents. Due to its transparency, light passes through without being blocked, and the cornea, iris, lens, vitreous humor, and aqueous humor together form a sophisticated optical system for the reception of light in the human body.

The refractive system is characterized by low absorption rate, high transmittance rate and strong focusing ability, which enables the laser to pass through the refractive system and reach the retina after entering the eye. At this time, the laser energy density on the retina can be increased by thousands of times or even tens of thousands of times, and the high temperature of the retina will lead to necrosis of the photoreceptor cells, resulting in irreversible damage and even permanent blindness.

Far-infrared laser damage to the eye is mainly targeted at the cornea, while the ultraviolet laser is mainly absorbed by the lens, corneal damage, will cause keratitis, conjunctivitis, the injured will also be accompanied by photophobia, tearing, vision loss, congestion, and other symptoms; lens damage, there will be cloudy lens phenomenon.

As the damage caused by laser irradiation to the eye is irreversible, so when using it, we must pay great attention to the protection of the eyes, wear goggles, maintain a certain safety distance, and strictly abide by the relevant rules and regulations, in order to fundamentally avoid the occurrence of injuries.

At present, most of the laser injuries are accidental exposure accidents, and a few are complications caused by laser treatment. After the human body suffers from laser injury, it is necessary to take sufficient rest and avoid light. If the trauma is serious, it should immediately contact a medical professional, and if necessary, it can be treated with glucocorticosteroids.

Before using laser for operation, one should check whether there is any light leakage and close the position where the light may leak; the working environment should be kept sufficiently illuminated, and protective structures made of light-absorbing materials should be used in the surrounding area; the individual should first check whether the goggles and protective clothing are intact.

In conclusion, laser can cause serious damage to the human body, but to a large extent, we can avoid it through scientific norms.