Turn an eye to the sky before skiing, the Massachusetts. Society for the Prevention of Blindness warns weekend skiers. Snow blindness, though misnamed, can be a painful souvenir of too much time on the slopes without adequate visual protection.

Actually, snow blindness is not blindness and isn't caused by snow. Correctly called solar photophthalmia, it is sunburn of the sun's ultraviolet rays off the glistening snow or ice. While generally affecting the unprepared skier, snow blindness is not unknown among mountain climbers, the Eskimos, and even polar bears.

Quality sunglasses or dark goggles are the best safeguards against snow blindness for the skier planning any length of time in the sun. Darker or neutral gray lenses with a light transmission averaging 20 per cent will screen the potentially-harmful ultraviolet rays. For safety make, these lenses should be of shatter-resistant safety glass or plastic. Tinted eyewear of ordinary glass offer an additional hazard to the eyes of a skier who falls or grases a tree limb on a downhill run.

Like a summer sunburn from the beach, the victim of snow blindness may not feel it until several hours afterwards. The first indication will be a slight visual discomfort like a speck in the eye. This worsens until the eyes burn as though full of grains of sand, with accompanying frofuse flow of tears and swelling of the eyelids. The patient will dread the sight of bright light.

Call a physician to examine all cases of snow blindness. Barring any complications, the acute symptoms will disappear in six or eight hours, and most of the visual discomfort will be gone within 48 hours.