SPECTACLES OUT OF DATE

Timaru Herald, Volume CLVII, Issue 23215, 31 May 1945, Page 2

SPECTACLES OUT OF DATE

“Contact” Lenses In Next Decade The next decade may see spectacles become as outmoded as the bustle. In their place persons with imperfect eyesight will wear “contact” lenses, whicn conform to the shape of normal eyes, and are completely invisible. They fit over the eyeballs and under the eyelids. Already about 20,000 Americans have discarded glasses in favour of contact lenses, and 5000 new customers are being added yearly, states t the Melbourne “Argus.” Seven years ago it cost about aOO dollars to manufacture and fit a pair of contact lenses. The cost to-day is 100 dollars, because of improved materials, polishing methods, and fitting techniques. Most expense is due to the skill required hi matching the lenses to individual eyes. Experiments now being conducted may _ eventually lower the cost to 30 or 40 dollars. The moSt important advance has been in the use of plastics instead ot glass in the manufacture of contact lenses. The newly developed art of grinding and polishing plastic now makes it possible to produce contact lenses which will correct every kind of eye defect that can be compensated by ordinary spectacles. The only exception is that the new invisible lenses cannot be made as bifocals. The risk of a contact lens breaking and injuring the eye has been eliminated by the. adoption of plastics. Actually plastic has been found to protect the eyes even against hard blows. In a motor-car accident recently flying glass cut the driver's eyelids, but damaged neither the contact lenses he was wearing nor his eyes. A girl machinist was hit by a steel fragment, which flew directly against the cornea of the eye. The blow made a deep crack hi her plastic lens, but did not injure the eye. Contact lenses do not fog with mist or spray, and they can be used to hide unsightly scars which distort the appearance of the iris. A few actresses have changed the colour of their eyes with tinted lenses.

One Disadvantage One disadvantage is that it takes several weeks to become accustomed to wearing contact lenses. The process of inserting them is painless, but at first they begin to irritate the wearer a few hours after the lenses are slipped over the eyeballs. After several months the average person can keep them on for about six hours at a stretch. Last year Army Air Force doctors were amazed to discover one pilot with seriously deficient eyesight who had gone through an 18 months’ flying course with contact lenses. Eager to become a fighter pilot, he had managed to pass six different physical examinations, flown long missions, night and day, and completed training with flying colours. He had steeled himself to wear contact lenses as long as 12 hours at a time. It was only during the final rigid physical checkup, before assignment overseas, that a physician discovered his secret. The officers reluctantly took back his wings, because the regulations strictly provide that Army fliers must have perfect vision. But they conceded that he was as good a pilot as any member of the squadron. The plastic material from which contact lenses are made Is polymethyl methacrylate, one of tbe newest resins. Tin oxide is used lo polish the plastic, since It was found that, rouge normally used for glasses is too abrasive. The greatest strides have been made in the hitherto laborious mid irritating tusk of lilting contacts to the wearer. The method was discovered through one of those freak accidents winch have advanced science on a nmnber of occasions. Au oculist was making a routine try-out of a pair of lenses. They have a tiny dome-centre, which must not touch the cornea of the eye. The operator was using fluorescln liquid, and ii strong while light to examine the tit. lie wanted more light, but instead of switching on the spare while light, he mistakenly pressed the button controlling the blue beam for examining veins Under the blue light fluorescln showed brilliant yellow where the eontiu-l lens find not touched the cornea. Where the lens came in touch with the cornea die chemical appeared r. much darker shade. Thus the oculist was able to (.■Il wiiere the contact lens required giHiding to make It n perfvet. tit The contact eyeglns.'i principle Is not new Tlie Britl h astronomer Sir John Herschell fli it uggsstsd the Idea in 1827 it was adopted in 18ti7. when the first glass louiiut lets, was made. But II W.il hot until 1(1 the lute 30 „ that i!<si teclinlqilci arid mutriLih rlr.ide contact ieti.'.i ■< a lOinrhsri lull.i feii lble I'll' num