ACCOMMODATION

A B B D E F G And K L M N O U R C T Y P X C H W E I

Accommodation - change of refractive eye power, providing the ability to clearly see objects that are at different distances. The physiological mechanism of accommodation lies in the fact that while reducing eye ciliary muscle fibers is relaxation of the ciliary girdle with which the lens is attached to the ciliary body. This reduces the tension of the lens bag, and it becomes more prominent due to its elastic properties. Relaxation of the ciliary muscle leads to thickening of the lens. The innervation of the ciliary muscle is carried oculomotor and sympathetic nerves. Accommodation of the eye is possible within the limited and the nearest future (most distant) points of clear vision. The first is determined by the smallest distance, where you can read the fine print; second - greatest distance at which the object clearly visible in the absence of accommodation. The increase in the refractive power of the eye optical system, achieved with a maximum voltage of accommodation, called its volume, or strength. The amount of accommodation decreases with age due to reduced elasticity of the lens.

Under the spasm of accommodation understand it more or less long period of tension, and continued after his eyes ceased to record a close subject. Thus, spasm manifests increased eye refraction and usually occurs in young people at high visual load for injuries eyes violation of innervation of the ciliary muscle, under the influence of certain drugs (such as pilocarpine).

Central paralysis of accommodation due to the defeat of the nucleus of the oculomotor nerve due to various intoxications and infections (syphilis, encephalitis , influenza , etc.) Or of the oculomotor nerve in trauma, tumors, meningitis, and so on. D. Peripheral paralysis of accommodation there for bruises eyes, ingestion or instillation atropine in the conjunctival sac preparations. Paralysis and paresis of accommodation are characterized by the inability to distinguish the fine print at a close distance. In paresis of accommodation is sometimes observed distortion of the shape and size of visible objects.

For the treatment of spasm and paralysis of accommodation of the eye patients are referred to an ophthalmologist.