[The theory of floating eye model]. / K teorii modeli plavaiushchego glaza.

Analytical construction of the eye floating was carried out. Buoyancy equations were deduced including the equation for dynamic equilibrium at various eye (head) orientations in space. Design formulae were derived for evaluating buoyancy force on the eye, negative pressure, stability and compensational (heeling) forces of the eye muscles.

[Functional significance of a floating eye model]. / Funktsional'noe znachenie modeli plavaiushchego glaza.

The role of the floating eye model in the organization of situating and producing eye micromovements was studied. There is presented a hydromechanical model of orthophoria of latent and obvious squint. It is shown that the multiformity of obvious squint depends on the variety of combinations of nonuniform forces in the right eye aparting from the left one, which is the result of nonuniform deviations of both eyes from the norm, and heterophoria is the result of combinations of uniform forces aparting and of analogous deviations of both eyes form. It is shown that the concomittant squint is caused by the existence of different polar heterophoria at both eyes, and their multiformity is the result of their various combinations. The essential necessity of the eye floating for the organization of micromovements--eye tremor and drift is established. It is shown that the eye tremor which takes place under incomplete tetanus of the musole is possible only at optimal equilibrium of the eye and absence of friction they both are at floating. The non-muscle moving character of the eye drift is revealed. It proceeds under the influence of hydromechanical forces of aparting and nonequilibrated gravity of the cornea as a result of weakening of the eye movement muscle under fixation. The cause of the optic, axis divergence (OA) with optic line (OL) and the necessity with it of postnatal development of the eye dioptrics under active influence of the motor apparatus was discovered. Physiology of the eye floating, new conclusions and a hypothesis concerning the model are discussed.

[New determinations of the eye rotation center and criteria for the formation of its membrane in terms of the floating eye model and experimental support of the latter]. / Novye opredeleniia tsentra vrashcheniia glaza i kriterii formirovaniia ego obolochki v svete modeli plavaiushchego glaza i éksperimental'noi podtverzhdenie modeli.

It is well known that the eye is a phylogenetically stabilized body with rotation properties. The eye has an elastic cover and is filled with uniform fluid. According to the theory of covers and other concepts on the configuration of turning fluid mass we concluded that the eyeball has an elliptic configuration. Classification of the eyeball is here presented with simultaneous studies of the principles of the eye situation. The parallelism between the state and different types of heterophory and orthophory was studied. To determine normal configuration it is necessary to have in mind some principles of achieving advisable correct situation of the eye in orbit. We determined the centre of the eye rotation and showed that it is impossible to situate it out of the geometrical centre of the eyeball. It was pointed out that for adequate perception the rotation centre must be situated on the visual axis. Using the well known theory of floating we experimentally determined that the centre of the eye rotation lies on the level of the floating eye, just on the point of cross of the visual line with the optical axis. It was shown experimentally on the basis of recording the eye movements in the process of eyelid closing that weakening of the eye movements is of gravitational pattern and proceeds under the action of stability forces, which directly indicates the floating state of the eye. For the first time using the model of the floating eye it was possible to show the formation of extraeye vacuum by straining the back wall. This effect can be obtained without any difficulty, if the face is turned down. The role of negative pressure in the formation of the eye ametropy, as well as new conclusions and prognostications about this new model are discussed.

[Torsion movements of the human eye. IV. Passive body movements, effect of skeletal muscle reflexes, opticokinetic torsion tracking]. / Issledovanie torzionnykh dvizhenii glaz cheloveka. IV. Passivnye dvizheniia tela, vliaanie refleksov skeletnoi muskulatury, optikokineticheskoe torzionnoe proslezhivanie.

A comparative study of torsional movement of the eye in passive and active tilting of the head and body of the object was carried out. Similarity of torsional movement of the eyes in passive and active movements was shown. It was found by the method of exclusion and selective stimulation of vestibular, cervikal, lumbar optokinetic reflexes, that neither the cervikal, nor lumbar reflexes elicited spontaneous torsional movements of the eyes and had no influence on them. A direct study (coinciding with rotation direction of the stimulus of head rotation) and the reverse (noncoinciding) torsional tracing of a rotating disc and tracing without head movements was investigated. During direct tracing depression of saccades and extention of the slow phase of torsion was found; during the reverse one--a decrease of the eye drist and increase of the amplitude and number of saccades. Phenomena of a seeming acceleration and deceleration of disc rotation etc. have been observed. It was found that with torsional saccades vision was retained. The presence of optokinetic control of phases of torsional eye movements formation has been recorded. Tracing without rotation of the head was accompanied by torsional nistagmus. Possible causes of incomplete stabilisation and optokinetic torsional tracing are discussed.

[Torsion movements of the human eye. III. Rapid phase of torsion]. / Issledovanie torzionnykh dvizhenii glaz cheloveka. III. Bystraia faza torzii.

Kinematic characteristics of torsional saccades and their peculiarities were investigated. The torsional saccades were found to occur simultaniously in both eyes and had the same size and duration. It was shown that the peak velocity and the duration of the saccades depend on their amplitudes. The number of the saccades decreased and their sizes increased when the head tilts were faster. In the case intervals between the saccades decreased up to 20-30 ms. The likeness of the torsional movements and rotatory nistagmus was discussed.

[Torsional movements of the human eye. II. Slow phase of torsion]. / Issledovanie torzionnykh dvizhenii glaz cheloveka. II. Medlennaia faza torzii

At different experimental conditions quantitative characteristics of the slow phase of the torsional eye movements were investigated. We found the torsional drift to increase when the head tilted faster and its velocity was bigger in the dark than in the light. Asymmetry of the drift velocity was found on moving the head to and backward. It was shown that the sign of the asymmetry did not depend on rotatory movements of the cup (the suction device for eye movement registration). At the same time electric stimulation of the labyrinth changed the sign of asymmetry and without head tilting led to the torsional eye movements (nistagmus). Some subjects were able to decline the number of the torsional saccades at will, and as a result the eye made a drift up to tens of degrees long. Possible causes of imperfect vestibular and optokinetic compensation in the eye trosion were discussed.

[Torsional movements of the human eye. I. Torsional movements on inclining the head towards the shoulder]. / Issledovanie torzionnykh dvizhenii glaz cheloveka. I. Nekotorye osobennosti torzionnykh dvizhenii pri naklone golovy k plechu

The characteristics of the torsional eye movements during head tilting were investigated. Different conditions were used in the experiments. The subjects were in sitting and lying positions in the light and in the dark. A new method of recording with the suction device of Yarbus and the simple optical system allowed to have records without some redundant components of movement. This made record processing less complex and more accurate. The torsional drift in the slow phase of the eye movement was found present under any conditions. When being recorded simultaneously both eyes in man were in identical and synchronous movement.