Let's talk today about what a femtosecond laser is. What are the main principles of his work and how does he help to correct vision?
Когда в начале девятнадцатого века наука достигла a level that could look into the structure of the atom, a new direction arose - quantum physics. The first task was to determine how and why small electrons do not fall on the heavy nucleus of an atom. The previous theory, based on Maxwell's equations, asserted that any moving charge emits a field, therefore, loses its momentum. Thus, an electron that moves in an orbit around the nucleus must continuously emit and eventually fall on the nucleus. Bohr expressed the idea that in an atom, electrons can only be at certain distances to the center, and a transition from one level to another is accompanied by either the emission or absorption of energy. This theory was subsequently explained within the framework of quantum physics. The presence of stationary electronic levels has opened the way for such an invention as a laser (femtosecond including).
Once scientists understood the structure of the atom, theywanted to learn how to control the state of an electron. Under normal conditions, an electron, which for some reason is at a high level of the atom, tends to fill the lower levels, if they are free. During the transition, the energy is emitted in the form of a quantum of light or a photon. But the transition between any two levels generates different quanta of light. But if many electrons pass simultaneously from a higher level to a lower level, then a stream of many identical photons will appear. The applications of this flow are endless. For example, a femtosecond laser cataract removes. In yttrium-doped ruby, a level was found with the so-called inverse population: when electrons are more readily collected at a high level, and then all together go to a lower one. The main components of the laser are as follows:
The resulting pulse at the output can be continuous or discrete. A femtosecond laser, for example, is of the second type.
All these consoles denote part of the whole. Milli is one thousandth of something, for example, a meter. That is, a millimeter is 10-3 meter. Femto prefix means that something weighs or stretches in 10-15 times less than a certain unit. Accordingly, a femtosecond laser has a very short pulse. And in every second there is 1015 pieces of pulses.Why do we need such an unimaginably small amount? The fact is that the laser power depends on how much time electrons accumulate at the inverse level. With continuous generation, the power of lasers can not be high. But the shorter each impulse, the higher the yield. Many processes occur much longer, and for a final goal such a short pulse is not noticeable. The receiving system seems to be a continuous laser. In this case, the coherence and power of the outgoing beam is much higher.
Cataract is a clouding of the lens.A person who develops such a visual defect may not even know about it: when cataracts develop on the edge of the pupil, vision is not disturbed. But if the turbidity occurs in the center of the lens, then you can not notice the loss of vision is impossible. The main reasons for this change in the eye are four:
The physical cause is the same - the protein containedin the lens of the eye, begins to degrade, to collapse. This process is called protein denaturation. In the case of the lens, the destruction is irreversible. Earlier, old people with white eyes completely depended on their relatives, since they were actually blind. However, now this disease is successfully treated.
Traditionally, treatment meansinterference in the human body, which does not violate its integrity: the sore throat is treated with pills and hot tea, cut a finger - with ointments and a bandage.
But in this case, radical treatment is an operation.Usually, this word means wounds, stitches that heal for a long time, pain and loss of a normal lifestyle. In the case of cataract surgery, you do not need to be afraid, because the incision is usually very small, 2-3 mm, no blood vessels are cut, local anesthesia.
Stages of the operation:
The procedure lasts no more than 15 minutes, after which the person can already go home himself.
It is at the stage of transformation of the old lens intoemulsion used femtosecond laser. Ophthalmology knows another example of the use of lasers - correction of myopia and astigmatism. But this is a completely different story.
Сразу назовем один существенный недостаток – этот The way is quite expensive. However, in all other parameters it is better than previous methods. According to reviews, the tissue surrounding the lens is less damaged, conversion to emulsion takes place faster, the size of the resulting particles is smaller if a femtosecond laser is used in the operation. Feedback on such an operation is extremely positive both from patients and from doctors.
We already mentioned that using lasersmyopia is also corrected. However, until recently, different equipment was used for this operation and treatment of cataracts. The main thing for the patient is the quality of the operation, but the clinic that provides such services would like to spend not so much money on the devices. In this case, the Victus femtosecond laser will help out: it can be used to perform three different operations. In this case, you only need to change the settings.
