Invisible Eye

B. F. SYLVESTER

SOME 35,000 persons in this country and an estimated 50,000 in Germany wear contact lenses — invisible plastic shells which fit over the eyeball and under the eyelids. The number here would be much greater but for the manpower shortage. Many technicians have gone to war, and the remaining ones work from twelve to sixteen hours a day trying to handle the most essential cases, of whom about 75 per cent are in military service.

Sir John Herschel, the astronomer, suggested contact lenses in cases of diseased eyelids in 1827. Near the end of the century they began to be made for cases of conical cornea which could not be corrected by ordinary glasses. The first useful contact lenses were made by Moller of Wiesbaden, an art ificial-eye maker, who made them out of blown glass in the same way that artificial eyes are made.

The modern development of contacts started just after World War I when technicians of Carl Zeiss at Jena, Germany, found a way to grind optical corrections on his blown-glass lenses. Patients in this country had to wait three months for lenses. The fittings were on a trial-and-error basis with stock lenses: when one was found that fitted, it was sent to Germany for the optical correction.

German technicians were jealous of their discoveries and would not sell tools to Americans, who had to make their own. About eight years ago methods of taking impressions and molding plastic lenses were developed. These were for fitting only, because at that time a technique had not been tievised for putting an optical surface on plastic. So a final lens had to be made of glass. Two years later a process was found for grinding optical corrections on clear plastic.

The impressions are made with a substance called Negoeoll, now being replaced by moldite, which does not have to be heated. The eye is first anesthetized. The substance hardens in a few minutes. From it a cast, is made and then a temporary lens. After the temporary fitting, the optical correction is made, and then the patient is tested for what is called the chemical fit. A solution of distilled water, sodium bicarbonate, and sodium chloride fills the space between the cornea and the slightly bulged front of the lens. The patient first finds a solution which permits him to wear the lens in comfort, then one which keeps the lens clear for the longest period of time.

The average person wears a lens for about four hours before it becomes cloudy. One patient kept the lenses in from Friday to Tuesday without experiencing discomfort or haling the lens cloud up. One aerial gunner changes his fluid once a day. An architectural draftsman and basketball player changes the fluid twice a week, lint at first most people find that they must change every two hours.

The movies make ingenious use of the contact lens in a number of ways. Movie criminals now hide their identity bv wearing contact lenses and throwing off the police. In Miracles for Sale you see Henry Hull disguising himself by wearing contact lenses. Furthermore, you see how the thing is done.

Bela Lugosi used contact lenses wilh a layer of green fluorescein in Dracula to make himself look more horrible than usual. The fluorescein gives a terrifying effect under a flashlight in a dark scene. Fluorescein happens to be an essential part of lensfitting technique and has solved one of the most difficult problems: how to gel an exact corneal lit.

The filming of A ortlnvest Mounted came to a sudden slop one day when some sharp-eyed person looked at Indian chief Walter Hampden and said, “Huh-uh. You can’t be a blue-eyed Indian.” Wally Westmore, make-up man for ihe producer, was sharp, too; for a few weeks later the actor reappeared as a brown-eyed Indian. He was wearing contact lenses with a brown caramel filler between cornea and optics.

However, if Mr. Hampden had had gray eyes and wished to have blue eyes, or light brown and wished to have dark brown, the contact lens people could have tinted the lens and no special solution would have been required. They have a number of women customers for whom they have changed the eye colors. Before the war they were working on some other colors by tinting the lens, but this has nothing to do with the fluid that lens wearers must employ. There are useful purposes for tinted lenses, such as protection to persons exposed to excessive glare, but cosmetic tinting has been stopped for the duration.

The cosmetic appeal of contact lenses, for both men and women, is not being encouraged these days. The manufacturers try to supply the people who need them — mostly cases of irregularly shaped cornea, but some astigmatism, myopia, and cataract-operated cases.

Contact lens wearers report curious things. One patient does well with her new lenses except on the second floor at Marshall Field’s store in Chicago, where they are uncomfortable. Another reports the most satisfaction when the weather is cool, and especially when walking and skating. In the house they are no good for her.

Contact lenses have given normal vision to a Chicago girl with what is reported to be the greatest correction in medical history, minus It) in one eye and plus 19 in the other. That is, she was extremely farsighted in one eye and nearsighted in the other. Before acquiring contact lenses she got around by wearing spectacles with one eye blacked out.

There was the aerial gunner who wanted combat stat us rather than that of an instructor. Although for various reasons the chances of his using contact, lenses successfully seemed poor, in less than six weeks’ time he was wearing his lenses all day long and he qualified.

The cosmetic reason is behind many patients’ decision to give up the old glasses and to wear invisible ones. Actresses and singers on the stage and in the movies wear them. Then, too, there are baseball and football players and swimmers who need optical corrections but cannot wear spectacles.

Industrial workers exposed to extraordinary hazards are not supposed to depend on contacts to protect them. But one drill press operator felt a stinging blow against, one of her contact lenses and found that a piece of steel had struck it. Unprotected, she might have lost that eye, but the steel did not pierce t be lens. Anot her girl, a welder, found sparks had struck and imbedded themselves in her contact lenses, which again had probably prevented serious injury.

A truck driver on the Alcan highway now wears contact lenses. He drives in temperatures of 70 below, he said, and he wanted glasses with automatic: defrosters such as the eyeball provides. A few men in the Canadian Navy have been permitted to wear contact lenses; they find them excellent for lookout duty in rainy weather when other glasses become obscured by spray. One patient is a baker. His ordinary glasses become covered with flour, but contact lenses are kept clear by his natural windshield wipers, the lids.

The Army Air Corps has been conducting experiments on what protection the lenses offer against dust. A dust tunnel has been set. up with good results. Experiments have been made in a pressure chamber on patients wearing contact lenses while in altitudes ranging from below sea level to six miles high, and temperature ranging from 126 to 40 below zero. There was little change in the visual effectiveness on account of the altitude, and no fogging or discomfort results from the temperature changes.

Contact lenses are not regulation as yet with our Army Air Corps, though they are with 1 he R A F and the RCAF. American pilots have to start with 20-20 vision. They may put on contacts after that if they like, but they cannot use contacts to correct the vision to 20-20.

The lenses are inserted either with the fingers or with a rubber suction cup. A1 ost people, at first, find that they have little or no control over sensitive and fluttery eyelids. An ophthalmologist had an idea for a foot-powered device which pulled up the upper lid and pulled down the lower at the same time to make insertion of the lens easier. A technician made the contraption but il did not come into general use; there was too much machinery, and most persons didn’t need it.

Contact lenses are not expected to supplant ordinary spectacles for general use. Aside from the trouble of removing and inserting them, they cost from $150 to $200 a pair. This expense is offset to some extent by the fact that contact lenses seldom have to be changed as spectacles do.

At last report, there were six cities where contact lenses are made: New York, Chicago, Detroit, London, Budapest, and Jena. However, there are a number of cities in this country where persons whh special training take the eye impressions and send them to the laboratories where the lenses are made.

Trumpet Vine

By PADRRAIC COLUM

A GLOOMY tree that marks a blackened shed
Across which knots a vine with reddish flowers
That move as fingers and are deep as combs.
Inviting flowers! But whom do they entreat?
Oh, none whose lives are bound to this confine:
Then presently there is that fairy thing
Of body that is all a metal gloss,
A bird that makes its wings invisible,
And here are beakers for the hummingbird.
A gloomy tree a blackened shed beside:
Foiling the green-dark with blood-orange glow,
The Trumpet Vine waves its deep-vesseled flowers.
  1. A former city editor of the Omaha World-Herald, B. F. SYLVESTER has written for various magazines. This is his first appearance in the Atlantic.