GENERAL ARTICLES

BUILT-IN GLASSES

Geoffrey Hewelcke December 1 1945
GENERAL ARTICLES

BUILT-IN GLASSES

Geoffrey Hewelcke December 1 1945

BUILT-IN GLASSES

Here's plastic in your eye! Contact lenses bring fresh hope to the near-sightless and glamour to the fugitive from horn rims

Geoffrey Hewelcke

DROP your glasses on the sidewalk and they’ll bounce. Kick them and you may scratch their surface—but the scratch can be polished away, Wear themߞand they vanish . . . completely.

We’re talking about eyeglasses. Not spectacles, of course, and actually not even glass. Specifically we’re talking about contact lenses, which fit under the lids, close against the eyeball; lenses made of transparent plastic, which will bounce where glass will break.

In Canada perhaps 2,000 persons are wearing these contact lenses now. Hut they pass unnoticed in the crowd because the lenses are invisible. There is, literally, nothing to be seen. There are no rims, no popeyes, no heavy lenses that make the wearer look as if peering through a goldfish bowl. The eyes look normal.

It is only in the last three years or so that contact lenses have been freely prescribed to Canadians, only in the past two years that the lenses have been actually manufactured in Canada. Even yet there are

not more than 35 oculists and optometrists in Canada trained in the technique of prescribing and fitting them. But demand for these invisible glasses is growing. And within the next few years many, many more Canadians will be wearing them.

Most of them will not be wearing contacts just because of vanity -because they think they’ll look better without the standard glasses. They’ll be wearing them because contact lenses can, in their particular cases, improve vision more than regular glasses, or because these lenses make it possible for them to hold jobs which they could not otherwise hold.

The Man Who Was Blind

CONSIDER the case of a man living near London, Ont. Some 25 years ago he lost almost all vision in one eye when a metal sliver was flung into it by a machine he was tending. Nine years ago an even greater tragedy befell him. A wire lashed across his face while he was at work. The end tore out his good eye.

For all practical purposes the man was blind. He had to quit his job. He had to learn Braille. He walked with a white cane, for he saw only light and dark with his remaining eye and no detail of any

sort Two years after the tragedy his wife bore a son. The man never knew him except as a sometimes vocal shadow.

A few months ago he was in London and dropped in on an optometrist, who fitted him with a trial contact lens as an experiment.

The man could see!

For the first time in nine years the world had detail and color. Of course the trial lens was not perfect. Adjustments, measurements had to be made, but he submitted eagerly. He ordered a lens, but before it could come to him from Toronto he was back with his seven-year-old son beside him.

“Put in that trial lens for just a minute,” he begged. “I’ve never really seen my boy—and I do so want to see him.”

The metal shaving that pierced this man’s eye 25 years ago destroyed the crystalline lens under the iris, left the cornea deeply scarred. Vision was gone from that eye, and no spectacles would help. Light and shade were the only impressions he could get.

The reason a contact lens restored sight in his case is that the buffer liquid between the contact lens and eyeball neutralized the light-distorting scars on the damaged cornea—that portion of the eye covering iris and pupil—while the perfectly spherical grinding of the interior surface of the lens created the equivalent of a new cornea. To replace the magnifying value of the missing crystalline lens of the eye an additional corrective Continued on poge 56

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power was ground into the exterior of the plastic.

Maximum correction was assured to this man, as to all other wearers of perfectly fitted contacts, because the lens moves freely with the eyeball, the pupil remaining centred at the point of best vision. There is no distortion such as wearers of thick-lensed spectacles suffer when they have to glance sideways through their glasses.

This means that contact lenses can be particularly useful to sufferers from extreme shortand long-sightedness; to those who have scars on their corneas as a result of accidents or operations for cataracts; to those, like this man, who have had the crystalline natural lens removed from the eyeball, and to those who have conical corneas—a distortion which results in scrambled vision for its sufferers.

Most of these unfortunates have had to wear glasses as thick as bottle bottoms, which distorted their eyes and sometimes their appearance. Women, particularly, suffered from this necessity—bearing in mind Dorothy Parker’s famous dictum that “Men seldom make passes at girls who wear glasses.”

Take the case of a Toronto girl engaged to a soldier who had been overseas for five years. During those five years the girl developed eye trouble, terrible trouble. She had 18 operations for cataracts and when they were finished her sight, even with spectacles, was 10% of normal in one eye and 36% in the other.

In order to do her work she had to

wear spectacles that made her eyes look like a bullfrog’s, and she had not told her fiance about her troubles because she did not want to worry him. But now he was due back soon and she didn’t want to meet him, wearing those heavy glasses.

She had contacts made. Vision in the eye that was 10% of normal was improved to 33%. Vision in the other eye was improved to 89%.

“And the girl?” I asked the man who fitted her.

“She’s happy beyond words . . . Funny thing, though—about a month after her boy friend came back from overseas she asked me whether I thought she should tell him about her contact lenses. She felt that it might make a difference. I told her that if he really cared for her it wouldn’t . . . They’ve been married a month now...”

Science Collided With Plastics

Though contact lenses are new in Canada, their principle has been known for a long time. More than a century ago Sir John Herschel, the British astronomer, experimented with them, thinking they might be particularly useful to sufferers from diseased eyelids. Later, contact lenses of optical glass were made in Germany, but proved to be unpopular because they did not fit the eyeball exactly.

Also ordinary optical glass is soon dulled by the natural secretions of the human body, which etch its polished surfaces.

It was not until the age of plastics collided with the science of optics that a new type of lens became possible. This new lens is made of methyl methacrylate, a colorless alcohol dc-

rivative which has high optical values, is capable of being ground and polished, and is unaffected by the acids and alkalies of the body. Furthermore, although extremely light, it is very tough. Changes of temperature will not cause it to shatter. Neither will a drop on a concrete floor. Its hardness is less than that of glass, approximating that of copper. This means that contact lenses must be carefully handled to avoid scratching—usually they are carried in a velvet-lined box— but scratches can be polished out.

Even more important than the material’s immunity against shattering and corrosion is the fact that it can be molded into any shape through the application of heat and pressure. This means it is possible to make each contact lens fit a specific eyeball— something that was impossible with the older style glass lenses made in Germany before the war.

How in the world, you ask, is it possible to get a mold of a human eye?

It is not as difficult as it sounds. A few drops of local anaesthetic—a /-£% solution of pontocaine and a little adrenalin—are dropped into the eye, by a physician, to desensitize the eyeball.

The patient lies on his back. A solution of a special powdered molding material, similar to that used for dental impressions, is poured into a molding cup whose edges are inserted under the eyelids. The material hardens within two or three minutes into a rubbery jelly and then is removed—a perfect mold of the eyeball’s face.

From this mold a cast is made in dental stone. This replica is sent to the contact lens manufacturer, who uses it to make still another set of molds in which he presses out the rough shape of the lens.

Then follows the exacting work of grinding: first of all a cavity in the interior of the lens to fit over the sensitive cornea of the eye and then the grinding of the optical corrections, both on the inside and the outside of the shell.

The corrections are ordered by the fitter, who has a stock of basic contact lenses which he tries on the prospective wearers. With these lenses in position the patient is put through the regular routine of reading charts and looking at diagrams through extra lenses of the type with which every wearer of spectacles is familiar These tests determine the corrections to be ordered.

Let’s Look at a Lens

The lens, when completed, is about an inch long horizontally, a trifle less than that vertically. It is curved to fit the eyeball exactly. The eyelids

cover about a quarter of an inch of the lens at the top and bottom.

There are few sensory nerves on the white part of the eyeball, which explains why contact lenses can be worn without discomfort. The contrary, however, is true of the cornea, which is one of the most pain-conscious spots of the human agatomy, as anyone who ever got a cinder in the eye can attest.

To prevent contact with the cornea j a hollow is ground in the lens. Wearers of contacts fill this hollow with a | buffer fluid. Various fluids are used. One of the most common is a solution of salt and baking soda in distilled water.

When the contacts arrive from the manufacturer the fitter inserts the lenses filled with buffer solution to which has been added fluorescine—a chemical which glows weirdly green when ultra-violet light is directed at it.

This is to make sure that there is space enough left in the hollow above the tender cornea. If the cornea should touch the lens anywhere a brown spot in the glow marks the point of contact —and back go the lenses for another touch of grinding.

The wearer is trained to insert them, avoiding bubbles in the buffer liquid, and generally can slide them into position within 20 seconds. A little suction cup on a stem is used to remove them.

The buffer fluid serves as more than a mere lubricant. It acts as one of the elements in the compound lens correcting the vision of the wearer. Also— now and again—it gives trouble.

“A perfect buffer solution that will serve everyone without deterioration is still to be invented,” said A. J. ! Brent, who started Canadian manufacture of these lenses two years ago, in Toronto.

“The eye secretions of some people | are more acid or more alkaline than i average and these variations will affect chemically the buffer solution, which then grows cloudy. Also the cornea may itself absorb some fluid. When this happens people see rainbows around anything they’re looking at. The cure is to change the solution or to rest the cornea by taking out the lenses for an hour or so. Accustomed wearers of contact lenses usually change their solutions once a day anyway.”

“Accustomed wearers?”—How long does it take to get used to wearing contact lenses?

Contacts cannot be slipped into place and worn without any discomfort in the beginning.

The experts advise that contacts should be worn for only an hour a day during the first week, for two hours a day during the week following, so that

gradually their owner can discover for himself how long he can wear the lenses without taking them out.

One specialist in contacts told me of a patient who wears his lenses for 17 hours a day without even taking them out to change the buffer solution.

“I’ve read in medical records of a man who wore them for two weeks straight without removing them,” he said. “But that I would like to see.

“It boils down to this,” he continued. “If you need the extra vision that contacts give, you’ll make yourself get used to them.”

What is average wearing time? Many people wear them all day, changing solutions every three or four hours. But seven to eight hours without removal of the lenses is average, according to E. J. Fisher, lecturer on subjects including contact lenses -he wears them himself—at the College of Optometry of Ontario.

“That is,” he warns, “for people who have really accustomed themselves to wearing contacts. Many people buy them just for the sake of vanity, and then find that they are too much trouble. If they leave off wearing them for a few weeks they must train their eyes all over again.”

In Canada contacts cost an average of $175 a pair. This is a great deal more than glasses cost, but for those who really need contacts almost no expense is too great.

Besides, Mr. Fisher and other

specialists point out, contact lenses differ from ordinary spectacles in that they do not have to be renewed every couple of years, even for people with severe eye ailments. The buffer fluid compensates for changes in the shape of the cornea well enough to make contact lenses last for at least 10 or 12 years. If corrections are then necessary they can be ground* into the existing lenses.

A famous surgeon recently developed conical corneas. Light rays entered from the side and he saw a nose in the middle of a patient’s forehead or where his ear should be. Obviously it was impossible for him to operate under these conditions—but contact lenses corrected his trouble.

Another surgeon found that operating room temperatures would make perspiration run into his eyes, blinding him at critical moments. He overcame the difficulty with contacts.

Workers with strong chemicals that give off eye-irritating fumes use them. Naval officers, who found salt spray or steam clouding ordinary glasses, find their own eyelids excellent windshield wipers for contact lenses. Actors and actresses wear them. One of the returned men trying out for the Queen’s football team this fall wears them— and writes that for the first time in his life he can actually see the football in play.

You can’t wear glasses playing football, hut you can wear contacts.