The Bridgeport evening farmer., 1917-09-12
ESKIMOS CAREFULLY GUARDING AGAINST
 SNOW BLINDNESS


 up by a recent exploration through the Polar regions is the fact that Es-- kimos know as much about the eff fects of snow blindness as our own scientists, and for a great many years have protected themselves from sun glare by means of goggles. pr. Jud- son Daland of the University of Penn sylvania recently gave a very inter- esting interview on his trip to Alas ka and Siberia, the islands in the Behring Sea and Arctic Ocean. He says that conjunctitives, cataract, and snow blindness are very common ocu- lar diseases among Eskimos and that generations of bitter experience have taught them the necessity of protect ing their eyes from the suns rays. The ,Eskimos have also learned that goggles are necessary on cloudy or dull days. Neglect to protect them selves with goggles has caused many of our own Arctic explorers to fall victims to snow blindness.
 The Eskimos are unusually inven- tive in making their goggles. for there are few materials available. The [range of the temperature, from zero to seventy-five degrees below, makes the use of metal or ivory out of the
 question. They therefore make them from wood, to fit not only the eyes
 but the forehead and cheekbones.
 They exclude all light, except that en-
 tering two very narrow horizontal
 sits in front of each eye. No two
 pair of goggles are exactly alike The
 inner surface around the slits is usu- ally blackened..
 The Eskimos have protected them
 selves from snow blindness a great deal longer than civilized people, for it is only comparatively recently that the danger from ultra violet rays in light has become known to science and experiments have been made to protect the eyes of human beings from them
 So far has this science gone, how ever, that in Russia it is now cus-
 tomary to equip cows with sur
 glasses. Very recently an item ap-
 peared in the press to the effect that klO,00O cows on the steppes of Russia
 have been provided with dark glasses to protec their eyes from the glare oj
 the sun on the snow. It seems tha,
 the food of these cows is gras. which crops up above the snow ir places where the ground Is not deepI, covered, and the sun glare sometime , blinds the cattle so that they canno
 readily find their food.
 In searching for glass to protec the ewes from the bright glare of srn ) light, both in the winter time and i, , certain conditions in summer, a. eres : many glasses have been invented ant , tried. Some of these are still stron, 5 in the public favor, while others hay been discarded. One of the most popu
 lar forms Of sun or snow lglasse comes in various shades of amher while still another is a dull snolr
 color. Green and blue are also some
 times used. The best solution of tn problem, however, is found in wear
 ing glass invented a few years az l by Sir William Crookes, the note x English scientist who has a grea y many other discoveries to his credit 3 This glass possesses the unique char g acteristic of excluding the dangeron : ultra violet rays whife not changin s the colors of. objects. As eyeryon e knows. when green, blue or ambe . glasses are put on. the, colors of oh e 1ects are changed to suit the tint C & the glass. This has been considere Q very dangerous, because if worn cor i, tinuously there is a great danger ths
 the eye will become color-bInd f
 certain colors.
 # With the glass invented by Sir Wi . liam Crookes, however, it is not DO,
 sible to become color-blind, since a
 of the visible colors are admitted f
 the eye in practically their fu
 strength and without any modifics t ton of color va1ue
 ? White light can be split m int r. many colors by means of a prism : L. we all know. We find the fapniIi. d clors of the rainbow varying from l. deep red to very faint violet. This y called the visible spectrum and y made up of light of a varying ra D of vibrations. each variation in il e vibration producing a different col, d effect upon the eye. Just as there a, t. some sounds too high pitched for u l. human ear to detect, there are vari Id ton of light too rapid for interpret p ton os color by the human eye. Gu n side of the band of red. there are a humber of rays of very slow frequel
 ley, which are called the infra-rt