Health resort treatment of eye diseases caused by ischemia]

The authors discuss the results of ophthalmodynamometric tests used for the assessment of cerebro-retinal vessels reactivity following carbon dioxide baths and "peat collars". An analysis of systemic and local blood pressure in the ophthalmic artery measured with Weigelin and Lobstein technique enables to assess changes in blood pressures following a/m balneologic procedures. It was found that blood pressure does not change parallelly due to the mechanism of cerebral autoregulation. Transient decrease in blood pressure in the ophthalmic artery is produced by the dilatation of the internal carotid artery indicating a potent vasodilating action of carbon dioxide.     

A combinatorial study of the rigidity of planar structures

Summary A combinatorial method is presented for examining the rigidity of planar structures. In this approach, an expansion process is used for the formation of a statically determinate substructure, known as a -tree of a structure. The algorithm of Lováz and Yemini, and the method of Sugihara are employed for the recognition of the elementary subgraphs, during this process.With 4 Figures     

Solar ultraviolet irradiation of human cornea, lens, and retina: equations of ocular irradiation

Photochemical damage of ocular tissues by solar radiation depends on the spectral composition of the radiation in the environment, the geometry of the coupling of that radiation to the eye, the spectral transmittances of the ocular components and any auxiliary lenses used, the spectral sensitivity of the irradiated tissue, the accumulated exposure dose, and the action of repair processes. This paper provides formulas for quantitative estimation of corneal, lenticular, and retinal UV irradiances from the sunlit environment under clear sky conditions. Applications of these formulas for ocular irradiation will be presented in subsequent papers for the cornea, lens, and retina, and the results will be evaluated using weighting functions for the sensitivity of ocular tissue.