Optronique

Optronique is a term where are gathered two historically different scientific denominations:

one refers to the Optique, science whose origins go back to several centuries - even at several millenia - since already at the Babylonian and the Égyptiens, then at the Greek S and the Romain S, the first laws on the reflection was stated and the first demonstrations of focusing were carried out;

the other refers to the electronic which is, without question, a creation of the 20th century.

The recent association of these two technical fields was and will remain still a long time generating of new concepts and equipment, as well on the military level as on the civil level. Often, in similar cases, one needs spectacular events to reveal with the public the capacities and the existence even of such technical or scientific innovations. Thus, the war of the Gulf, with the beginning of the year 1991, was it particularly revealing for the non-specialists and the uninitiated persons. For the first time, the not specialized press largely used the optronic terminology.

Although this term - optronic - was introduced with the beginning of the year 1970, it remains sometimes still (even in the specialized milieux) certain confusions of interpretation between the terms which we detail then:

Optical;
Optical electronics;
Optoelectronic;
electro-optical (acousto-optics, magneto-optics);
optronique

Instrumentation

The term Optique is reserved, of course, with the components, subsets and units comprising of the lenses, mirrors, prisms, etc and contributing generally to the deflection and/or the focusing of the photons.

The term Optique electronics is reserved for the devices with vacuum, deflecting and/or focusing electrons, technique presenting of the analogies with the deviation of the photons.

The Optoélectronique indicates mainly components transforming: maybe of the incidental photons in electrons, it is the case of the detectors of visible light, of radiations ultra-violet or infra-red; maybe of the electrons in photons as it is the case in many sources of light and in particular in the transmitting diodes of light and the lasers diode.

The electro-optical applies to components whose optical characteristics can be modified by application of a tension or an electric current (liquid crystals are an example).

More specific terms are also used when there is interaction between:

a acoustic signal and a optical Material: it is then of a phenomenon or a component Acousto-optics;
a Magnetic field and an optical material: it is then of a phenomenon or a component known as Magnéto-optique.

When it relates to the Technologies, the optronic terminology must be held for the concept of equipment or system calling upon those which have just been stated and with other techniques and technologies which make it possible to construct a whole of functions.

Thus the optronique one leads to equipment or systems suitable for associate:

of the components Laser, Television, Infra-red;
of the devices Optical S, Optoelectronic S, electro-optical S;
of the Mechanism S and Servomechanism S;
of the gyroscopic bodies ;
of the circuits of analogical treatment;
of the devices of Digital processing (Treatment of the signal, image processing);
of the Visualizations;
of the devices of recording;
of the circuits of transmission.

Neurophysiology of the visual System

See also: visual System

The term of optronic can be employed, answering perfectly the conditions of its definition, relating to the eye and the vision at the human being.

Indeed, the eye contains the Cristallin which behaves as a lens to focus on the Rétine the light which passes through the Pupille. The photosensitive cells of the retina, cones and sticks, generate a transmission of electrons until in the optical nerve when they take delivery of a photon.

Moreover, the Accommodation is the function which allows the " setting with the point" of an image on the retina when the object observed moves on the line of glance. That corresponds to a variation of the dioptric power of the crystalline lens, by a variation of its radius of curvature. On the anatomical level, its variations are supported by the muscles ciliaires and radiate of the eye, whose antagonistic actions must balance to obtain the clear vision at any distance from observation. These are these muscles whose senile relaxation is with the cause of the Presbytie. Their actions for which the sympathetic Nervous system and the parasympathetic Nervous system have prolongations around the crystalline lens, are thus managed by the autonomous Nervous system and the pair of the IIIe cranial nerve.

Certain handling of experts exists, acting on the human nervous system and in particular the accommodative function by means of refracting lenses.

The purpose of they are generally to relieve a accommodatif stress leading to a pseudo-myopique behavior which appears towards adolescence. It is what one recognizes like the syndrome of the " myopia of the étudiant". In this case, such an assumption of responsibility makes it possible to avoid a habituation of the ophthalmologic patient to glasses of myope who consolidates it in his defect, and then involves a real myopia, generally evolutionary, by the lengthening of the eye. The best remedy to be proposed remaining rest and relaxation! …

In other cases, in particular for the patient presbyope, one can involve the orthoptic patient in practice to compensate for a defect of convergence, with or without double vision. Indeed, the convergence of the lines of glance and accommodation are two functions managed jointly on the level of the core of IIIè cranial nerve whose nerves are prolonged at the same time in the muscles ciliaires and radiate of the crystalline lens and in the order of the driving muscles of the eye. Thus there exists at the neurological level a relation accommodation-convergence, result of a good evolution making it possible to facilitate the fusion of the images coming from the two eyes and the development on brought closer objects, by accelerating the answer of the nervous system. The constriction of the pupils and it also associated with these two functions, to reduce the field of vision of close, removing a fuzzy vision of the images in bottom.

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