Farsightedness, hyperopia, thick glasses, rubbed the bridge with the fingerprints from the rim … Familiar words and feelings associated with them? Nowadays, almost every second man and one woman aged over 50 years wear glasses with a thick glass! This means that about 40% of middle age have a visual impairment by type of presbyopia. Under the terrible title, "presbyopia" understand global process that occurs throughout the body. Eyesight is designed so that all the light falling on svetovospriimchivy layer (retina) is 4 light-refracting first layer – the cornea, anterior chamber fluid, lens, vitreous body. Each layer of its functionality and purpose. vSeychas will discuss the form of eye as a whole.

The clarity of images on the retina is affected not only the ability of the lens to change its curvature and hence the focus. Also on the clarity affects shape of the eye – in fact at the same power index and different focal length, sharpness, too, will be different. According to the theory of Bates in the normal form eyes changing every moment – that contribute to the six eye muscles – 2 and 4 skew lines. Oblique muscles of the eye pose a horizontal ellipse in longitudinal section, that is, squeezing it from the outside toward the center, thus increasing the necessary focal length. A straight – from the eye creates a vertical ellipse, that is, squeezing it from front to back, reducing the required focal length, which can reconstruct the lens. The fact is that during adolescence, youth, maturity, normally straight and oblique muscles work in harmony and with equal force.