A NATION IN SPECTACLES.

Star (Christchurch), Issue 8751, 13 October 1906, Page 2

A NATION IN SPECTACLES.

■WTiat the Demands of Modern Life

are Loading To.

(By HENRY G. MACLAURIN, in the "Daily Mail.")

The Englishman who reads without the aid of spectacles will be an object of curiosity before another century dawns. We shall, indeed, by that time be largely a nation of spectacle-wearers. The average town-dweller will 1 deem a pair of spectacles to be as nerfessary an adjunct to his personality as a. pair of boots, a hat, or an umbrella. Not that a rapid deterioration of the national eyesight is to be anticipated. Far from it. Spectacles , will be worn not only by people with defective eyesight, but by those whose visual power is normal. < HOW NATURE MAKES LEKSES: First let me draw attention to a remarkable organism situated a fraction of an inch behind the transparent front surface of the eyeball— by name, the crystalline lens. This lens practically is identical with an ordinary magnifying glass of small compass and high power. Only between it and the lens of commerce there is a vital point of difference. <. , For example, were it possible for a man to have the crystalline lens removed (as in a cataract operation), andreplaced by an artificial lens of equivalent power, he would have the following curious experience. Everything outside the radius of a few feet would be seen distinctly; everything inside this radius would be seen indistinctly. He would recognise objects, a yard, a furlong, a - mile distant; but a page of printed matter held ten inches from his eyes would present a confused, undecipherable blur.

This admits of a simple explanation. An artificial lens is non-adjustable, whereas a lens used for near work requires to be of higher focus than one used for. distance. • In the human eye nature provides for this contingency in. a remarkable and altogether unique way. The crystalline lens is invested, at its circumference, with a powerful muscle — the ciliary. This muscle contracts upon the lens, thereby reducing its area and causing it to bulge; the lens by this means assumes a greater convexity; becomes, in fact, of higher power, therefore adapts the eye for near vision. OVERWORKED EYES. The action of the ciliary muscle is automatic. When a person looks into the distance, the muscle is in a state of i relaxation, allowing the lens to assume its minimum convexity. On the contrary, fixation of the eyes on a near ob> . ject is the signal for the ciliary immediately to contract, thus oausing the lens to assume its maximum convexity. Our admiration for this wonderful provision of nature is not unmingled with apprehension. The demands of present-day commercial life are causing the willing ciliary to be worked to excess. Use, in a word, is giving place to abuse. CHIEF CAUSE OP BAD EYESIGHT. An interesting comparison here suggests itself between outdoor workers on the one hand and indoor workers on. the other — i.e., between those whose eyes are rarely used for close work and those to whom close/application is habitual. In the former case the ciliary muscles are well-nigh permanently at rest-strain, consequently, is ,an unknown quantity. In the latter case the ciliafies are always ina ctive operation, buffering (according to the precise nature of a 'person's employment) .maximum contraction for eight, ten, or even twelve hours daily. Frequently these exacting conditions havfetobe fulfilled by persons totally unfitted by temperament and constitution to discharge them. No matter. Necessity admits of no alterin ative, save one from which the brainworker and bread-winner shrinks. Bub is there no way of relieving the ciliary muscle of its arduous and exhausting task? If so-, obviously the brain worker has a valuable asset placed at his disposal. . I would say yes — on this ground. That a convex lens of specific power, by being placed before the eye during the time the latter is used for close vision, adds to the strength of the crystalline lens, and .thus allows of a proportionate reduction in the cotftraction of the ciliary muscle. Even a perfect eye may gain by the aid of lenses (the writer, indeed, can vouch for this, from practical experience) ; though^ of course, where the eye is defective, the result-, ant benefit is immeasurably greater.

SIGNALS. A brain-worker using his ciliary muscles many hour© daily and neglecting available precautions must one day suffer from eye-strain. Eye-strain, in effect, is synonymous wiifli over-worked eye-muscles. There is a certain /point at which the ciliary begins to lag. Beyond this point the effort to sustain its contraction is a war against Nature. The worker is immediately conscious of Nature's distress signals; is conscious of them, but may not heed them. Too often, there is, for him, no respite. Stop he would, if he could ; but stoppage would entail precisely those consequences which most men seek to avoid. Loss of situation, for instance. Situations, nowadays, are an elusive quantity ; once lest)- they are not easily regained. To-day, it is an easy matter for a man who drops out of the running to go to the wall; easier than some people, with superlative wisdom and assured circumstances, think. The worker does not .drop out. He continues his uphill fight against adverse conditions; overdraws his reserve of nervous energy ; saps his vitality of nerve and brain. Distressing headaches and other inconveniences are a part of hie daily life. These frequent-

ly are the forewarning of a otfenptafa breakdown. The case is not overstated. Doubtless many causes contribute to this breakdown, but ey«r strain certainly is not the least. For many years there was *n un» willingness on the part of the medical faculty to give to eye^strain its proper place in their calculations. This unwillingness, however, is rapidly passing away, inasmuch as many doctors now recommend to a qualified oculist all patients whose symptoms lead them to suspect the existence of eye-strain* This is as it should be. A mechanical defect can be corrected by mechanical means only. To prescribe drugs in oases of headache and other forms of nerve* trouble without first having ascertained the state of the eyes is equivalent' •to pouring water into a bucket witit a hole in it. . . - That the number of . 6pectacle-wear<M« has largely increased during $he . last few years is due not to.ihe fact that eyesight is more defective than dottier-, ]y, but beoause, owing to the advance in the^eciehoe 1 of eyesight testing ami' spectacle fitting, it is possible to give , relief through the medium of glasses, in cases where it was deemed impossible. .''...'■' ./.;• ■/"_•.- '[.<■ BATTALIONS OF SPECTACLE WJEA»EKS. ';■'-■>■? Perhaps publio education' has hact some part in oompafising this result, fiSr^ people now seek the advice of the 1 ; oculist where formerly they went with;;! all speed to the doctor. A marked > feature, too, of the present day, is tie diminishing prejudice against .the. wearing of spectacles. Judging by th^'.iecent tests to which school children hayebeen subjected, we may safely assump.t that the next generation -ml scarcely < be in advance of tibia in the matter- of.; good eyesight, and there will be armie*: of spectaole-wearers where there iar.if' new merely battalions. ; „/..• ■ ,; W,