The results of the experimental research of vertical refraction in 1980–1992 in Turkmenistan are presented. More than 100 cycles of observation were made. It was found, that the refraction varies randomly in a large range. The value of the refraction angle in the bottom layer of the atmosphere cannot be pre-calculated in a sufficient accuracy according to the meteorological data and basing on measurements on the refractive basis or the atmosphere’s model accepted. This can be explained through differences in the optical properties of a static atmosphere (which is the default used in the calculation) and real one, a turbulent atmosphere.