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The purpose of this study was to identify the mechanisms of water-exchange processes in the lens and the vitreous chamber of a rabbit. Fluid transport processes in the lens were studied in vitro by the change in mass when immersed in the washing environments of the lenses, with the addition of an inhibitor of the active transport system Na+,K+-ATPase and without it. The direction of movement of aqueous humor was studied in vivo by the displacement of the fluorescein using biomicroscopy and "stopped diffusion". The removal of aqueous humor from the vitreous chamber was investigated by changing the concentration of the fluorescein in blood plasma taken from the vascular eye veins and the lateral ear veins, with increased or decreased pressure in the vascular system. It is established that water-exchange processes represent the physiological mechanism of "breathing" in the lens at the moments of accommodation "near-in the distance".
At a sight "in the distance" pressure in the flattened lens is minimal, therefore "fresh" aqueous humor enters the lens through its anterior capsule. The active ion transport system Na+,K+-ATPase, which is localized in the epithelium of the anterior capsule, promotes the osmotic transport of "fresh" aqueous humor and its further unidirectional diffusion from the anterior capsule to the posterior. Intensive receipt of aqueous humor maximally increases the inside the lens pressure to 6 mm Hg and translates the lens into a accommodation phase "near". ÃÂÂÂÂÂ¢he lens is maximally rounded and the greatest inside the lens pressure, which promotes the diffusion of "spent" aqueous humor through the posterior capsule. The movement of aqueous humor in the vitreous chamber takes place in the direction of the retina along the gradient of the oncotic pressure. Excretion of aqueous humor from the eye's posterior part occurs through the eye's vortical veins into the total bloodstream.