Sense Organs

SENSE ORGANS provide the central nervous system with signals about changes occurring in the external environment or within the organism itself, which develops and acts in this environment. In this case, only part of the flow of impulses sent by the sense organs is perceived by us in the form of sensations (localized in the cerebral cortex), while the rest of the flow does not reach our consciousness but plays a very significant physiological role. This signaling from the sense organs constitutes a necessary link in the diverse processes of the central nervous system as an organ of mental activity up to its highest, specifically human forms. In bourgeois psychophysiology, sense organs are usually considered in a mechanistic isolation from the development and activity of the brain, of which they are in fact an instrument (Engels), and in turn the activity of the brain necessarily presupposes the functioning of the organism as a whole. On the other hand, bourgeois psychophysiology ignores the question of the profound uniqueness of sense organs and their role in humans, of the historically-laboratory basis characteristic of humans for their development with all the resulting consequences for the anatomy and physiology of sense organs as concrete-historical formations. At best, researchers limit themselves to merely noting the differences between human sense organs and those of animals. Moreover, bourgeois science and the profound crisis it is experiencing (in connection with the crisis of the capitalist system) are characterized by numerous attempts to use data from the study of sense organs for idealistic assertions about the supposedly fundamental natural limitations of human cognitive abilities, for "sophisms of idealistic philosophy" consisting in the fact that "sensation is taken not as a connection of consciousness with the higher world, but as a partition, a wall, separating consciousness from the higher world" (Lenin). All this requires a fundamental revision of the data of the modern doctrine of sense organs on the basis of materialistic dialectics, as well as recognition of their extreme limitations, including that material which is presented below. Sense organs are usually divided into three systems: exteroceptive (external), enteroceptive (internal), and proprioceptive (proper). The first system includes sense organs located on the periphery: organs of vision, hearing, smell, taste, and skin sensations (pressure, temperature, and pain). The second system covers the sensitivity of internal organs. The third system includes organs of muscle sense, located in the muscles, tendons, and joints, and organs of static sense, signaling about the position and movement of the body in space and located in the labyrinth of the inner ear: in the stato-cytes, or "hearing bubbles" (utriculus and sacculus) and in the semicircular canals. Sense organs are brought into an active state when irritated from outside or inside the organism. In this case, each sense organ is characterized by a "specific predisposition" or adaptation to a certain specific type of irritation, which is called adequate, or homologous irritant for a given organ. The retina is specifically adapted to irritation by light waves, the organ of hearing to sound waves, the organs of smell and taste to chemical irritations. However, sense organs can be excited artificially by other, non-specific irritants for them (inadequate, or heterologous irritants). For example, the retina can be inadequately excited by pressure or electric current, which belong to general irritants for various excitable tissues of the organism. Electric current can also inadequately irritate other sense organs: smell, taste, hearing, and skin sensations. All sense organs in this case exhibit a remarkable property known as the law of specific energy of sense organs (Johannes Müller); it should be mentioned that this outstanding physiologist was a representative of "physiological idealism", because, "for example, pointing out that the sensation of light is obtained from various kinds of effects on the eye, he was inclined to conclude from this the denial of the fact that our sensations are images of objective reality". - Whatever the nature of the irritant acting on a given sense organ, whether this irritant is adequate or inadequate, as a result of irritation, a specific type of sensation for this organ always arises. Thus, both when light acts on the retina, and when an electric current passes through the eye, and when pressure is applied to the eyeball, only a visual sensation always arises (examples: the appearance of sparks when striking the eye, flashes of light during the pulsation of arteries, which are known as the entoptic phenomenon of the pulse, etc.). The law of specific energy can be applied not only to broad categories of basic types of sensations (vision, hearing, taste, smell, etc.), but also to narrower, differentiated categories of types of sensations, in relation to complex sense organs. Thus, for the sense of taste, four main types of sensations have been established: bitter, sweet, salty, and sour. Each of these types of sensations - according to available observations - probably has its own terminal organs or sensory substance (experiments with isolated irritation of individual papillae on the tongue and with isolated exclusion of individual types of taste sensations by poisons). A similar assumption is also quite probable in relation to types of olfactory sensations. The law of specific energy also manifests itself quite convincingly in relation to skin sensitivity: the skin has separate spatially separated points of heat, points of cold, points of pressure, and - possibly - points of pain. Each of these points, when irritated in isolation, regardless of the type of irritant, gives only one specific type of sensation: electrical or mechanical irritation of the skin at these points gives a sensation of pressure, or heat, or cold. The specificity of sense organs is vividly illustrated by a paradoxical experiment: pointwise heating of the skin can cause a sensation of cold if heating is applied precisely to a cold point. In some cases, it is possible to obtain a similar paradoxical result of the appearance of a thermal sensation when cooling the skin. It is very important to emphasize that the specificity of sense organs manifests itself not only in relation to the type of sensation, but also in relation to the degree of irritability of a given organ by various types of irritants. Irritability in relation to the specific adequate irritant is much higher than in relation to the inadequate one. For example, the retina can be excited by an insignificant amount of light energy equal to only a small number of quanta, whereas for its excitation by various types of inadequate irritants, much greater energy expenditure is required (for example, electrical or mechanical). The intensity of sensations and reflex reactions arising from the irritation of sense organs depends on the strength of the irritant. Very weak irritation generally remains ineffective: it must not be less than a certain limit called the threshold of irritation in order to cause any response (sensation or reflex). With a further increase in the strength of irritation, an increase in the intensity of sensation occurs, but not continuously, but in jumps: the existing irritation must increase by a certain definite final quantity called the threshold of differentiation to give the first barely noticeable increment of sensation. At the same time, the greater the strength of the existing irritation, the greater the increase in this irritation is required to cause the first, barely perceptible increase in the intensity of sensation. For some sense organs, it has been possible to establish a quantitative relationship between the strength of the irritant and the magnitude of the threshold of differentiation in the form of the so-called psycho-physical Weber-Fechner law: thresholds of differentiation increase directly in proportion to the strength of the existing irritation, or the relationship between the magnitude of the threshold of differentiation, i.e., the smallest necessary increment of the strength of the irritant, and the strength of the already acting irritation always remains constant. This law can be expressed by a simple formula: where I denotes the strength of the irritation present at a given moment, ΔI is the threshold of differentiation, i.e., the smallest perceptible increment of the strength of the irritation, and K is a certain constant number characteristic of each organ. The fraction ΔI/I is called the relative threshold of differentiation and it is different for different sense organs. For example, for vision ΔI/I = 1/100, for muscle sense - 1/50, for skin pressure sense - 1/7 (for skin sense, relative thresholds of differentiation are different for different areas of the skin). Other formulations of the psycho-physical law are also often used: a) when the intensity of irritation increases in geometric progression, the intensity of sensation increases in arithmetic progression, or b) the intensity of sensation grows in proportion to the logarithms of irritation according to the formula E=K logI, where E is the intensity of sensation, I is the intensity of irritation, K is a constant.

However, this quantitative ratio does not have universal applicability in the physiology of sense organs; for those organs where it is applicable, it is valid only within certain limits: with very weak and very strong irritations, deviations from the Weber-Fechner law are observed. These deviations for vision, according to some researchers, can be reconciled with the law only if it is assumed that the constant in the Weber-Fechner formula changes at very low and very high intensities of irritation (Mac Donald, Allen; 1930). For hearing, the Weber-Fechner law is generally inapplicable and must be replaced by another formula (MacDonald, Robertson; 1930). It is extremely important to clarify the mechanism by which our sense organs distinguish between different degrees of intensity of irritation. The difficulty of the question lay in the need to reconcile this ability to distinguish the strength of irritation with the physiological property of 'all or nothing'. This property was first discovered in the cardiac muscle 60 years ago and consists in the fact that the cardiac muscle, when artificially irritated, produces a contraction whose intensity does not depend on the strength of irritation, provided this strength is not less than a certain value called the 'threshold of irritation'; with a weaker strength of irritation, the heart gives 'nothing', and with all other strengths of irritation, it gives 'everything'. Subsequently, on the basis of a series of studies, this principle was extended to skeletal muscle and nerve trunks: it is assumed that each individual nerve or muscle fiber responds to artificial irritation according to the law of 'all or nothing'; the cumulative effect of the entire muscle and the entire nerve trunk depends on the strength of irritation only because a stronger artificial irritation is capable of irritating a greater number of individual fibers. (However, to this day, the question of the applicability of the 'all or nothing' principle to skeletal muscles and nerves is not considered finally resolved.) The application of this principle to sense organs prompted researchers until recent years, when interpreting the Weber-Fechner law and in explaining in general the ability of sense organs to distinguish the strength of irritation, to adhere to a similar concept as for skeletal muscle and nerves. The majority of authors assumed that this ability depends exclusively on the fact that a stronger irritation, for example brighter illumination of the retina, is capable of irritating a greater number of excitable elements in the sense organs (for example, rods or cones in the retina or other terminal sensory apparatus in other organs). A new light was shed on this question by the extensive electro-physiological research on sense organs undertaken by Adrian with collaborators during the last 5 years; these works revealed new aspects of the excitation processes occurring in these organs. Adrian studied, using an amplifier from cathode lamps, the electric currents arising in the sensory nerves when the sense organs are irritated and accompanying the process of excitation. He investigated the isolated eye of a fish (eel), the organs of muscular sense (frog), the organs of skin sense (cat), etc. It turned out that under the action of constant irritation on sense organs, excitation of a non-constant but oscillatory nature arises in them: excitation consists of a series of rapidly following individual impulses which propagate further along the nerves to the central nervous system. It is very significant that the oscillatory nature of the excitation process in sense organs represents an analogy to tetanus of skeletal muscle and the rhythm of the heart. This analogy with cardiac rhythm is further deepened if one notes that with respect to sense organs, as with the heart, temperature causes a similar effect: an increase in rhythm. For example, in one experiment it was found that for the organs of muscular sense the total number of oscillations (impulses) at 15° = 330 per second, and at 5.8° only 190 per second (with the same strength of irritation). Further, it turned out that the intensity of individual impulses, determined by the intensity of the resulting action electric current, in many cases can be considered independent of the strength of irritation. However, with an increase in irritation, for almost all sense organs (except those perceiving pain), the frequency of impulses increases, varying from 5 to 100 (for the frog) and even up to 150 per 1 sec. (for the cat). Therefore, it can be assumed on the basis of electro-physiological research that the ability of sense organs to distinguish the strength of irritation, both in terms of sensations and reflex reactions, is based not only on the arithmetic change in the number of excited elements with different strengths of irritation, but also on the change in the nature of the excitation process in each excited element and, consequently, in each nerve fiber: in this case, however, only one aspect of excitation changes - the rhythm of impulses; the other aspect of excitation - the intensity of each constituent impulse - remains constant at all strengths of irritation. Thus, Adrian's works refute the idea of 'all or nothing' in its simplified, overly schematic application to sense organs, and at the same time lay a solid objective foundation for this same idea in a more precise and more limited formulation. To a similar result regarding the oscillatory nature of excitation in the visual organ, Frohlich (1913) also came earlier, working on the eye of mollusks using the electro-physiological method. Frohlich also showed that with an increase in illumination of the retina, the frequency of impulses increases from 40 to 90 per 1 sec. (for his object). Electro-physiological research has revealed a number of very essential aspects in the physiology of sense organs. Sense organs possess a refractory phase, i.e., after the occurrence of one impulse, they pass into a state of brief non-excitability lasting about 0.01 sec. In this respect, sense organs share the common property of all generally excitable tissues, which also have the property of a refractory phase (heart, skeletal muscles, nerve trunks, and nerve cells). Sense organs possess the property of adaptation: any irritation causes strong excitation in the first moments, but the intensity of excitation decreases in subsequent moments - the organ 'gets used to' the acting irritation without showing fatigue. This property of 'getting used to' (adaptation) is well known from subjective psychological observations: for example, sensations of pain, pressure, and smell 'dull' during the action of constant external irritation. For vision, adaptation can also be detected by self-observation. Light in the first moments of action on an eye that has been in the dark seems dazzlingly bright, and then the sensation of brightness weakens. Under certain experimental conditions - with a well-fixed eyeball - it can be noticed that an illuminated object can completely disappear from the field of view after approximately 20-30 sec. This phenomenon of adaptation, which characterizes sensation, is also revealed in electro-physiological research of sense organs; the rhythm of impulses sent by the organ along the sensory nerve to the central nervous system decreases during the action of irritation (Adrian, Frohlich). The ability to adapt is expressed to varying degrees in different sense organs. This ability is more pronounced for the sense of pain and to the least degree for the muscular sense. The other organs occupy an intermediate position in the same sequence as exists for the corresponding sensations. Consequently, the phenomenon of adaptation in the physiology of sense organs, if not exclusively, then to a large extent, characterizes the processes not in the central nervous system, but on the periphery, in the terminal apparatus. The electro-physiological technique also sheds light on a number of other very essential features in the physiology of sense organs, which until now were known only from subjective experience by the method of self-observation, for example on the phenomenon of successive images, the phenomenon of irradiation for vision, etc. These electro-physiological researches, the beginning of which dates back to the 19th century, lay the foundation for a new branch of physiology: general and special electro-physiology of sense organs. The further development of the doctrine of sense organs must be based on the extremely essential position of K. Marx that 'the formation of the five senses is a product of world history', and in particular that 'the eye became the human eye just as its object became a social, human object'. In the closest connection with these indications stands the indication of Engels that 'with the development of the brain (the main driving factors of this development - labor, and later, alongside it, articulate speech) went the parallel development of its nearest instruments - the sense organs. Just as the gradual development of language is invariably accompanied by the refinement of the organ of hearing, so the development of the brain is accompanied by the improvement of all senses in general'. The initial factual material for such a development is contained in a number of data from comparative morphology (see).

The architecture of the cerebral cortex, which indicates, not to mention the exceptional differentiation of the human cerebral cortex, a strong development in it of the peri- and parastriar fields, as well as the physiologically closely related fields of the inferior parietal lobe—this closest substrate of the complex 'gnostic' mechanisms that perfect the activity of the sense organs. On the other hand, extensive material is provided by neuro- and psychopathology, which reveals both the 'mechanisms' mentioned above and the active, structuro-physiological, inextricably linked with phylogenesis and with the history of the individual's practical experience, character of the activity of the sense organs (cf. the works of Weizsacker, which require a doubly critical approach to them, as indeed all sources referred to here). The doctrine of the sense organs must stand in especially close connection with the development of psychology, which in turn is subject to reconstruction on the basis of Marxist-Leninist theory. Statistics of diseases of the sense organs. Accounting for morbidity of the sense organs according to the international classification of revision 1920, on which the statistics given below is based, is conducted mainly by accounting for groups of diseases of the organs of vision and organs of hearing, which in turn belong to the department of nervous diseases. As for disorders of touch and taste, these are not isolated into special groups, but are included directly in the department of nervous diseases, while disorders of smell are usually accounted for in the department of diseases of the respiratory organs. All traumatic injuries to the eye and ear, as well as trachoma and night blindness (hemeralopia) are included in the groups of diseases of the sense organs, while in the latest nomenclature adopted by the USSR State Planning Committee in 1930, eye and ear injuries are isolated from diseases of the sense organs and belong to the group of traumatic injuries, trachoma to the group of infectious diseases, and night blindness to the group of diseases from inadequate nutrition. Gonococcal diseases of the eye (see Blennorrhea) are classified as infectious diseases in both international and Soviet nomenclature. Mortality. To get an idea of what proportion mortality from diseases of the sense organs occupied compared to mortality from diseases of the nervous system, one can refer to German hospital statistics. Thus, in 1928 in German hospitals mortality from diseases of the nervous system was 84.9°/sub>00/sub> (pro mille) of total hospital mortality, while mortality from diseases of the organ of hearing was 5.6°/sub>00/sub>, and from diseases of the organs of vision—0.3°/sub>oo/sub>. Further, for every 1,000 patients with infectious eye diseases, 0.6 to 8.5 died, with other eye diseases—1.3 to 1.5, with diseases of the outer ear—from 2.5 to 3.9, with diseases of the middle ear—from 18.8 to 21.1, and with diseases of the inner ear—from 22.7 to 28.1 (Table 1). Table 1. Mortality from diseases of the organs of vision and hearing in German hospitals for 1925-28 (per 1,000 patients with the corresponding disease). Diseases 1925. 1926. 1927. 1928.1 Infectious diseases 8.5 1.4 3.9 19.7 22.7 0.6 1.3 2.5 19.2 28.1 5.9 1.5 2.7 21.1 25.0 1.6 1 Other eye diseases .... Diseases of the outer ear . . Diseases of the middle ear . . . Diseases of the inner ear . 1.3 ! 3.0 1 18.8 ! 25.8 A detailed breakdown of morbidity of the sense organs is available for the city of Moscow for 1926 (year of census). Per 1,000 population it was 106.5 for eye diseases, and 35.3 for ear diseases. Of these, 38.0 were for conjunctivitis, 28.5 for refractive anomalies (including myopia 5.6), 4.0 for foreign bodies in the eye, 2.8 for trachoma, 1.7 for cataract, 0.2 for night blindness, and 0.1 for nystagmus. Of diseases of the organs of hearing—0.2 each for foreign bodies in the ear and deafness. By s e x morbidity is higher in men: for eye diseases it is 122.6, and in women 91.2, and for ear diseases—38.0 and 32.8 respectively. For individual forms, a predominance is observed almost everywhere in men (Table 2). The nature of morbidity by age and sex is illustrated in Tables 3 and 4. The role of profession in eye diseases is as follows. Traumatic injuries to the eye (Table 5) occur more frequently in professions of the metal industry, Table 2. Morbidity from eye and ear diseases by sex in Moscow in 1926 (per 1,000 population). | Diseases m. Diseases m. sh. { Conjunctivitis. | Trachoma .... Myopia . Other refractive anomalies . 1 Foreign bodies in eye . . 40.8 35.2 3.0 2.6 7.0 4.2 27.8jl8.2 1 11.6! 1.3 1 Night blindness | Cataract . . . | 1.5 Foreign bodies j in ear.....| 0.2 i 0.1 1.9 0.1 0.2 Table 3. Morbidity from eye and ear diseases by age and sex in Moscow in 1926 (per 1,000 population). Age m. z. Age m. Diseases of vision Before 1 yr - 4 » - 9 yr -14 » -19 » Before 1 yr - 4 » - 9 yr. 10-14 » 19 » 79.5 86.3 75.5 81.0 58.5 61.8 82.8 86.7 108.0 82.0 20-29 yr. 127.3 30-39 » 112.8 40-49 » 167.2 50-59 » 207.0 60 and over 205.7 70.4 79.0 134.7 152.7 134.6 Diseases of hearing 58.6 49.4 59.6 58.7 47.8 50.9 51.2 52.8 41.0 35.0 20-29 yr. 36.8 30-39 » 28.9 40-49 » 27.3 50-59 » 24.8 60 and over 22.4 As for night blindness, in relation to this disease, domestic influences can also be established. Thus, among persons with lower earnings, the indicators increase (Table 7—pre-revolutionary data). Table 7. Morbidity from night blindness and average monthly earnings. Professions Fitters machinists, Weavers .... Dyers . . . Painters . . . Average j Night blindness earnings in rubles (per 1000 workers)j 37.87 19.49 16.97 13.46 0.3 11.9 18.0 36.7 Morbidity with loss of working capacity is given in tables 8 and 9. For individual industries (Table 10), increased morbidity from eye diseases is noted in men in woodworking and sewing industries, and in women additionally in the industry for processing animal products. Conjunctivitis—in men in sewing, textile and processing of mineral substances, and in women—in textile and processing of animal products. From these comparisons it is clear that the professional factor does not manifest itself clearly, possibly Table 4. Morbidity from individual forms of eye and ear diseases by age and sex in Moscow in 1926 (per 1,000 population). ev s o o l B | B a ey re-ino-te-glass ev s$-~? * o И ev Foreign body in ear (abs.) se ^-, o Age ey a Sb ^ Й « a Й W o k >> a fo s £m«v B Я o ey ffl B йs; ago K§5 в K o o o m. m. 1 z. m. | z. m. z. m. m. m. 1 z. m. M. | Z. 1 Before 1 yr....... 60.3 63.7 1D 0.6 1.0 0.3 0.4 0.5 0.6 1 1 - 1-4. . 44.6 46.4 1.1 1.1 0.2 0.2 0.2 0.1 0.4 0.4 1.1 0.8 26 j 43 5- 9 yr. 28.6 36.6 2.4 2.7 0.5 0.4 1.2 0.8 2.9 3.1 0.9 0.7 - 24 20 ! 10-14 » 35.8 39.0 5.4 4.3 1.2 0.4 3.0 4.1 9.1 10.6 2.91 0.9 ! 15-19 » 35.0 33.3 3.9 1.1 0.5 7.7 5.0 11.6 7.5 17.41 2.2 20-29 » 44.1 29.2 3.8 2.1 0.7 0.3 12.1 5.9 16.1 8.2il;,9i 1.8 78 : 37 30-39 » 40.4 32.0 2.8 2.5 0.6 0.4 7.2 4.2 18.4115.3 16.0 1.5 42 1 31 ?, ю ' 40-49 » 40.9 39.2 2.8 2.9 1.2 1.0 6.8 4.8 74.5^6.0 11.7! 1.4 46 I 16 > 5&-59 » 37.8 41.8 4.7 3.5 3.9 6.9 4.9 113.259.9 5.2| 0.9 24 13 60 yr. and over 37.1 33.8 4.2 3.2 22.1 19.7 5.5 3.5 67.3,30.1 2.2 0.4 17 16 - especially high indicators are observed in turners and repair fitters—20 times higher than in the rural population of the same areas. Table 5. Traumatic injuries to the eye (workers of Moscow prov.—men 15-59 years, 1911-1915) (ratio per 1,000 workers). Woolen weavers ....

3.5 Paper weavers . .

4.3 Rural population

5.3 Scutchers....

6.2 Grinders.... 11.6 Stokers..... 14.0 Hammermen . . . 29.9 Turners 102.1 Repair mechanics 112.5 Conjunctivitis occurs more frequently among female workers in conditions of increased content of fine cotton dust and high temperature in the air. For example, among flinters and cotton spreaders, the rate is 37 times higher than among the rural population (table 6). Table 6. Conjunctivitis (workers of Moscow province - women 15-59 years old, 1911 - 1915) (ratio per 1,000 workers). Dryers.... 11.4 Waterproofers Rural population 30.0 Wool weavers. . . 42.6 Paper weavers . . . 49.4 Cotton sorters .........50.0 Galosh makers. . . . Hairdressers . . . Spinners... Flinters, cotton spreaders .... 106.7 64.9 70.8 72.3 78.8 This is because on the one hand there is a combination of detailed professions into entire industries, and on the other hand, a combination in groups of eye and ear diseases of various nosological forms. Among individual detailed professions in cotton mills, for example, conjunctivitis shows more regular gradations of rates (table 11). Among waterproofers and galosh makers, working in the most dusty conditions, the rates are highest, while among winders they are lower, and among administrative and technical personnel the coefficient is lowest. Disability. Of all those examined in the Moscow Bureau of Medical Expertise (1926), 2.9% were recognized as disabled due to diseases of the organs of vision, and 0.2% due to diseases of the organs of hearing. Thus, in the total mass of causes of disability, the role of diseases of the organs of vision is small, and that of diseases of the organs of hearing is negligible. Among office workers, the percentage of disabled is lower than among workers, both due to eye diseases (2.6 and 3.2) and ear diseases (0.2 and 0.4). Table. Number of cases of loss of capacity to work due to diseases of S.O. (Moscow and Moscow province 1925-1928) (per 100 insured). Years Eye diseases Including conjunctivitis Ear diseases m. m. m. I ,»„. 1 Total number of cases....... 2 042 1 471 ! 1 072 ' I Per 100 insured 2,5 2,1 1,3 1,0 0,7 0,7 ! чочр i Total number of cases . i \ Per 100 insured 2 881 1 953 , 1 385 2,6 2,1 j 1,3 1,0 0,8 0,7 1 :,„„„ / Total number of cases . 1 \ Per 100 insured 2 767 2 354 ¹ 1 223 1 185 2,3 2,3 1,0 1,2 0,8 0,7 i 1928 } Total number of cases . 1 \ Per 100 insured i 2 784 1 2,4 2 049 2,1 1 043 0,9 848 0,9 937 0,8 714 0.8 Ear diseases m. m. !K. m. m. i ж. 10,1 11,6 8,1 8,8 11,9 11,8 12,8 13,9 9,7 10,5 7,9 8,0 13,0 13,6 11,9 13,0 8,0 Ь,2 6,7 6,6 12,5 12,0 10,5 11,2 7,7 7,9 5,8 5,8 11,5 12,6 9,8 10,1 The severity of loss of capacity to work due to ear diseases is not as high, while due to eye diseases it exceeds the average (table 13). Table 9. Average duration of a case of loss of capacity to work from (Moscow and Moscow province 1925-1928). (in days) -n ей O. ч. Diseases of In Including conjunctivi- Diseases of By all diseases Years vision tis ear (without childbirth) m. m. !K. m. m. i ж. 10,1 11,6 8,1 8,8 11,9 11,8 12,8 13,9 9,7 10,5 7,9 8,0 13,0 13,6 11,9 13,0 8,0 Ь,2 6,7 6,6 12,5 12,0 10,5 11,2 7,7 7,9 5,8 5,8 11,5 12,6 9,8 10,1 The severity of loss of capacity to work due to ear diseases is not as high, while due to eye diseases it exceeds the average (table 13). Table 10. Indicators to a large extent depends on the increased content among office workers of persons with refraction anomalies. Hyperopia among female office workers, for example, constitutes about half of all defects noted in the visual apparatus. The influence of age is clearly manifested: hyperopes are more common among the elderly, while for myopia this tendency cannot be detected. Here rather the factor of professional selection operates: among office workers starting work (experience up to ^г/₂ year), the rates are significantly higher than among workers. This may be the result of previous school studies. Presbyopia among office workers occurs no more frequently than among workers. Here the influence of age predominates (table 15). Mass examination of occupations engaged in production shows that where losses of capacity to work in industry of Moscow in 192d g. (per 100 insured). Types of industry Diseases of organs of vision Including conjunctivitis Diseases of organs of hearing ; m. 0,6 0,6 1.0 0,8 0,8 0,4 0,3 1,6 0,9 0,5 m. 2,7 3,1 ! 2,3 | 2,9 i 2,4 | . 1,3 ! 2,4 1,5 1 2,0 ! 1,7 2,1 3,2 2,2 2,4 1,5 1,5 1,7 3,1 2,3 2,0 0,9 0,9 1,0 1,1 1,6 0,3 0,7 0,3 0,8 0,6 1,0 1,1 0,7 1,1 0,4 0,6 1,3 1,4 0,9 0,7 0,9 0,9 0,7 1,2 0,7 0,9 0,9 1,5 1,0 0,7 Woodworking ........... Processing of mineral substances . . . Processing of animal products . . . Pat. morbidity among industrial workers examined in 1925-1928 in Moscow is shown in table 14. Table 11. Conjunctivitis among cotton mill workers (1927) (per 100 insured) -

Including weavers . . . » » » winders Production workers . . . Auxiliary workers........... Junior service personnel ........... Admin.-tech. personnel . The highest morbidity of the visual apparatus can be observed among office workers, and among women it is higher than among men. This rate to a large extent depends on the increased content among office workers of persons with refraction anomalies. Hyperopia among female office workers, for example, constitutes about half of all defects noted in the visual apparatus. The influence of age is clearly manifested: hyperopes are more common among the elderly, while for myopia this tendency cannot be detected. Here rather the factor of professional selection operates: among office workers starting work (experience up to ^г/₂ year), the rates are significantly higher than among workers. This may be the result of previous school studies. Presbyopia among office workers occurs no more frequently than among workers. Here the influence of age predominates (table 15). Mass examination of occupations engaged in production shows that where there are suitable conditions for the development of conjunctivitis and blepharitis (for example, chalk dust, vapors of gasoline, acrolein, etc., as is the case in rubber production), the rates are highest (table 16); the absence of corresponding harmful factors in the environment is reflected in lower rates than average (3.0 for men and 2.0 for women). The duration of stay in a profession that contributes to the development of catarrhs of the conjunctiva of the eye is reflected in an increase in rates. Thus, for example, among paper weavers with an average rate of 5.4%, persons with experience of 1 to 5 years have a coefficient of 4.8%, with experience of 5-8 years - 5.9%, and with experience of 8 years and more - 6.3%. Table 12. Workers 3 ° ю and «o 3 co °? Рн 3 ft a >> 3,2 0,4 2,5 0,6 5,0 0,5 | 1,9 0,4 2,8 0,3 - 1,8 - 2,5 ~ ! 4,4 0,5 1 Office workers Total workers...... Metalworkers....... Printers........ Tailors........ Textile workers...... Chemists...... . . Builders ........ Local transport . . . Laborers and day laborers .... ...... 6 176 829 382 471 996 87 561 326 1 026 Total office workers .... Technical personnel . Accounting-control personnel ......... Med.-san. personnel . . . Workers of education Workers of communication .... 982 349 275 163 2,6 1,4 2,3 3,2 2,6 4,3 0,2 0 0,4 0,5 0 4 Table 13. Distribution of disabled workers by causes and groups of disability. Causes of disability Number of exam. A5-sol. Percentages By all diseases Diseases of organs of vision .... Diseases of organs of hearing .... 12 603 367 100 2,9 0,2 Percent distribution by groups of disability II III IV-VI 51,5 65,9 8,3 31,1 9,1 19,1 7,9 58,3 31,3 a b l. 14. Eye and ear diseases (per 100 examined). Auxiliary I

i Diseases Production workers m. ж. Diseases of organs of vision . . . Diseases of organs of hearing . . .

9,1 | 10,3 j 12,1 4,6 | 3,1 | 4,8 15,6 3,9 ab l. 15. Presbyopia in connection with age (per 100 examined). Age groups Production workers m. ж. 14-19 years 20-39 » 40-59 » 0,06 0,2 6,5 0,0£ 0,3 8,0 Auxiliary | workers | Office workers ж. 0,2 0,3 6,1 0,3 6,2 0,1 0,3 0,1 5,1 5,3 Table 16. Conjunctivitis and blepharitis in workers of various industries and professions (per 100 examined). Production m. ж. Rubber production . Galosh makers .... Tea packing .... Paper weavers . . . Paint production . . . Sausage production . . . Print factory . . . Confectionery factory Breweries 8,8 6,4 - 5,9 4,9 2,4 4,4 5,4 4,3 - 1,8 -. 1,4 1,2 0,6 0,4 0,5 0,6 coefficient 4.8%, with experience of 5-8 years - 5.9%, and with experience of 8 years and more - 6.3%. Morbidity of the organs of hearing among workers and office workers (examination 1925- 1928 in Moscow) ranges from 3.1 to 7.4 t a 17. Morbidity of organs of hearing (per 100 examined). Diseases Diseases of organs of hearing . . . Inflammation of the middle ear Hearing loss . . . Production workers Auxiliary workers Office workers m. ж. m. ж. 7,4 5,3 I 4,6 3,1 4,8 3,5 3,0 2,2 0,7 0,4 ^0,4 | 0,3 4,8 3,2 0,4 3,9 2,6 0,1 per 100 examined (table 17). Production workers have higher coefficients than auxiliary and office workers. The main component of the rates is inflammation of the middle ear.