THE HUMAN EYE. 
AN ESSAY READ BEFORE THE ATLANTA 
ACADEMY OF MEDICINE. 
BY H. F. SCOTJ, M.D. 
Reprinted from the Atlanta Medical and Surgical Journal. THE HUMAN EYE. 
BY II. F. SCOTT, M.I)., 
ATXiiLITTii., G-.A.. 
READ BEFORE THE ACADEMY OF MEDICINE. 
Reprint from the Atlanta Medical and Surgical Journal. 
Having been appointed by President Todd, to read an 
Essay before the Academy, you will pardon my selecting a 
subject appertaining to my speciality of diseases of the 
eye. 
You will doubtless agree with me, when I say that the* 
grandest of all optical instruments is the human eye. 
The telescope, which sweeps the sidereal heavens with 
a glance, and resolves far distant nebulae in the twinkling 
of an eye, is a marvelous product of human ingenuity. 
The microscope, which magnifies a razor’s edge to a 
finger’s breadth, and reveals the minutest organisms of 
animal and vegetable life, is scarcely less wonderful; but 
the human eye exhibits a higher mechanism than either 
or both of these notable contrivances of scientific skill. 
In discussing briefly the eye, its use and abuse, you 
will pardon us for prefacing our remarks with a bare out- 
line of the anatomy and physiology of this most impor- 
tant organ. 
The eye is a globe, spheroidal in shape, consisting of 
tlve sclerotic and choroid coats, of the cornea, which in 
construction closely resembles a watch crystal, and of the 
iris, a curious network of muscular fibres, interlaced with 2 
blood-vessels and nervous filaments, perforated by a pupil 
through which light is admitted into the inner chamber 
of the eye. 
In addition, it has tbe aqueous humor, crystalline lens 
and the vitreous body, which serve as so many refracting 
media, and besides impart shape and consistency to the 
eye. 
The eye, as thus constituted, is essentially a photo- 
graphic camera-obscura. 
In the rear, however, of the chamber of the eye, we 
meet with that remarkable expansion of the optic nerve, 
called the retina; its office is to receive the impressions of 
external objects, and by means of its conducting appara- 
tus, to transmit them to the sensorium where they become 
objects of perception. 
We are greatly indebted to Schulze for our present 
knowledge of the retina. 
According to his analysis, it is composed of ten distinct 
layers, all contributing in a greater or lesser measure to 
the purposes of vision. 
It remains to be stated that the eye is sustained and 
operated by six muscles, the four recti-muscles—superior, 
inferior, internal and external, and the two oblique—the 
superior and inferior. 
It need hardly be said, that it is lodged in well- 
cushioned sockets, and yet further protected from injury 
by bony processes, by the eyelids and by glands whose 
secretions lubricate and cleanse the eye. 
For the purposes of distinct vision, the crystalline lens 
is of transcendant importance. 
By its refracting power it forms a sharp, well defined 
image of the external object upon the retina, when other- 
wise the image would be blurred and greatly confused. 
The structure of the lens is not homogeneous, but it 
decreases in density from the centre to the circumference. 
In the living eye it is perfectly pellucid, but shortly 
after death, or when subjected to the action of heat or 
alcohol, it becomes opaque and impervious to the rays of 
light. 
, Upon this lens, also, depends the power of accommoda- 3 
tion; when an object is brought near the eye, its convexity 
is increased by the action of the fibres of the ciliary mus- 
cle, and the object is clearly perceived at a short distance. 
This faculty of accommodation or adjustment is mar- 
velous beyond expression. With equal facility it catches 
the light of Sirius several billions of miles from the earth, 
and perceives with distinctness the form and color of the 
violet at a distance of six inches. 
Without wearying you further with dry anatomical 
details, suffer us to speak at greater length of the uses of 
the eye. Much has been sung and written of the triumphs 
of blindness. The world is familiar with the story of the 
blind old bard of Scio’s rocky isle, and of him not less 
gifted who sung of man’s first disobedience and the fruit 
of that forbidden tree whose mortal taste brought death 
into the world with all our woe. 
Most of you have heard of Sande-rson, the blind math- 
ematician, and of Huber, the Swiss naturalist, who taught 
us the husbandry of bees. 
Not a few have read of Nydia, the blind flower-girl of 
Pompeii, who guided Glaucus, the Athenian, in perfect 
safety through the storm of fire, ashes and scoriae with 
which Vesuvius entombed the queenly city for a thousand 
years; and of that greatest prodigy, Laura Brigman, who, 
though blind and deaf, acquired a competent knowledge 
of history, geography and arithmetic by the tips of her 
fingers. 
We see in these instances an illustration of that law of 
compensation by which a merciful Providence very nearly 
equalizes the varied lots and conditions of men. 
Let us not too hastily conclude that the eye is of sec- 
ondary importance—after all, it is the chief inlet of knowl- 
edge of the external world; in this respect it far exceeds 
in value all the other senses. . 
If the human skull be indeed the dome of thought 
and palace of the soul, much more is the eye the window 
through which the mind itself looks out upon the mate- 
rial universe and becomes cognizant of its beauty and its 
glory—differing in its shade through all the gamut of 
colors, from the deep blue eye of an Annie Laurie to the 4 
languishing dark eye of an Andalusian maid, and is 
beyond all else the truest exponent of the character. 
No one who has read Milton’s exquisite sonnet on his 
own blindness, or his yet sublimer apostrophe to Light in 
the earlier cantos of ‘‘Paradise Lost” can fail to perceive 
that if the eye is once destroyed, creation, as to form, col- 
oring and the thousand other charms, becomes a universal 
blank. 
It may be well to say, in speaking of the uses of the 
eye, that we are morally responsible, in a measure, for 
what we see or fail to see—there is more in our subjective 
states than we often dream of. 
Shakespeare truthfully says that the lover sees Helen’s 
beauty in a brow of Egypt, and you all remember that 
Titania deemed Bottom a paragon of beauty, despite his 
assenine ears. 
Very much of our success in business or professional 
pursuits will depend upon the use we make of our eyes. 
Many things are best learned from observation. Quick 
perception, associated with a habit of close, unfaltering 
attention, is the great secret of genius itself. Parentsthere- 
fore owe it to themselves, but far more to their children, to 
oare for the eyes. Hundreds of dollars, however, are ex- 
pended on the teeth, to where one dollar is expended in se- 
curing the professional services of an oculist. Much of 
this neglect is due to popular ignorance, but is none the 
less damaging to the child. 
Some eye diseases are remarkably insidious in their 
approaches, and if not promptly arrested, in a very little 
while they become incurable. Prominent among these is 
Glaucoma. In its acute form there is high inflammatory 
action, attended with severe pain; yet, in these cases even, 
an expectant treatment is often adopted which merely 
.soothes and palliates, or, at the most, postpones the inevit- 
able result. 
In the chronic form of glaucoma the danger is seldom 
appreciated, and this fact, coupled with the dread of a 
surgical operation, occasions delay that is not less fatal 
to the vision of the affected eye. A timely resort to the 
simple and almost uniformly successful operation of Iri- 5 
dectomy, will at least preserve what vision may have sur- 
vived the ravages of the disease. 
You will pardon the seeming egotism of the remark 
when I say that I myself have witnessed numbers of such 
operations by Arlt at his clinics in Vienna, and in but 
few instances was there a failure, and then but a partial 
failure. In all cases everything depends on the prompt 
application of the knife. A very high authority, indeed, 
says that in estimating available time in glaucoma, hours 
must be reckoned as days, and in the fulminating form, 
minutes must be measured as hours. 
Another disease, which nearly always develops itself 
in childhood, is less insidious and less hurtful than glau- 
coma, but yet demands the immediate attention of the 
professional oculist. We refer to Strabismus, or squint, 
both convergent and divergent. In not a few cases the 
disease is the result of local paralysis, and in some of 
these cases, the usual severance of the muscle supposed to 
be at fault is a grave mistake ; it inflicts needless suffering 
without producing parallelism. 
In such, a constitutional treatment is indicated and is 
very often beneficial, yet, in the majority of instances the 
atropine treatment, accompanied by the use of suitable 
glasses, will be the most reliable remedy. Of course we 
recognize the necessity for the knife in the larger number 
of cases of strabismus. Our special object, however, in 
this connection, is to insist that in every case a skilled 
oculist be consulted before the vicious habit entails changes 
w’hich are beyond the hope of remedy. 
Another form of eye disease demands prompt atten- 
tion. We allude to Sympathetic Ophthalmia. Any injury 
done to one eye, especially if it involves the ciliary region, 
will be liable to develop sympathetic inflammation of a 
peculiarly obstinate and destructive character in the un- 
injured eye. In such an event, the immediate enucleation of 
the injured eye is imperatively called for. This affection 
sometimes follows an operation for the extraction of cata- 
ract; but it holds likewise in regard to all mechanical in- 
juries. 
In these cases (and they are constantly occurring) the 6 
patient should seek the counsel of an oculist, and he, if an 
expert, will extirpate, when needful, the offending organ 
and so prevent a total loss of vision. 
If deemed important for the purposes of this essay, I 
might speak in detail of Pterygium, conjunctivitis, cat- 
aract, etc., which are well known and comparatively well 
understood. Their presence is readily detected, and the 
needed treatment is seldom so urgent as in the forms of 
disease just mentioned. ' 
The remark which we made at the outset, that the eye 
was the grandest of all optical instruments, was strictly 
true in the sense there intended, but in another sense it 
needs material qualification. 
Statistics show that there is only about one person in 
every thousand that needs the restraint and regimen of a, 
lunatic asylum, but deQuincey wras not wide of the mark 
when he said that not more than one person in sixty is- 
perfectly sane. 
So, while there are comparatively few who require the 
professional services of an oculist, yet there is only a small 
percentage of our population whose vision is perfect, A 
large majority of those who compose this or any similar 
assemblage are really laboring under some infirmity of 
vision. 
The ideal eye, technically called emmetropic, is one of 
the rarest bestowments of the Great Creator; much the 
larger portion have either myopic or hypermetropic eyes— 
in popular parlance, they are either far-sighted or short- 
sighted. 
The deviation from the normal standard may be but- 
slight, and the individual may remain unconscious of the 
defect for years, but it nevertheless exists, and is the 
source of more or less discomfort and incapacity. 
The ophthalmoscope in the hands of a skillful oculist 
very often reveals defects of this sort that had not been 
previously suspected. 
In many cases these organic defects are congenital and 
in other cases they are the outcome of long-continued 
functional disturbances. In all cases, however, they may 
be benefited, if not fully remedied, by proper treatment 
or the use of suitable glasses.  7 
It will not be out of place here to notice a few of the 
causes of those diseases of the eye which are not strictly 
congenital. One of the most frequent of these causes, as 
will readily occur to all of you, is habitually over-taxing 
the eye. The eye, like every other organ, needs intervals 
of rest; it is not more certain that Assyrian or Egyptian 
sun will develop ophthalmia of a malignant type, than it 
is that reading by an insufficient light, whether natural 
Of artificial, or excessive reading by an adequate light, 
congests the organs of vision. 
The old maxim, ubi irritus ibifluxus, applies to this as 
well as to every other inflammatory action. 
A pleasant thing, says an inspired writer, it is for the 
eye to see the sun, but the softest sunlight of a May 
morning is stimulating to the optic nerve, and if too long 
continued, will irritate and inflame its delicate tissues. 
This injury is vastly intensified by the atmosphere of a 
crowded hall, where “bright lamps shine o’er fair women 
and brave men, and soft eyes speak love to eyes that speak 
again.” 
We would lay no needless restraint upon the innocent 
and healthful recreation of the young, but even a blind 
man can see that midnight revelry in a poisoned atmos- 
phere, amidst the flashing of wine cups and the glare of 
gaslight, is doing no little to produce premature blind- 
ness and even premature death. The Norman Curfew, 
hated as it was by our Saxon ancestors, would in these 
respects be a blessing to this age and country. 
Another grave abuse of the eye is the habitual reading 
of books and magazines printed in an exceedingly small 
type ; some of the cheap editions of our favorite poets and 
novelists are both a typographical swindle and a medical 
abomination; if they, had been studiously contrived to 
bring about one or another of the diseases known to the 
professional oculist, they could not have been more suc- 
cessful. ...» 
Our sanitary boards,who are devising ways and means 
to stay the march of pestilence, ought to bestow at least 
a passing notice upon this widely prevalent evil. And 
those who have in charge our public libraries should dis- 8 
countenance these publications, which, under the pretext 
of cheap literature, are sowing broadcast the seeds of eye 
disease amongst the youth of both sexes. 
It may be stated in general terms, that any influence 
which impairs the bodily health, thereby lowering the 
vitality of the system, is damaging in a greater or less 
degree to the eye. 
In harmony with this proposition is the fact that 
various forms of eye disease become almost epidemical in 
our crowdsd school-rooms and college halls. Other causes 
probably increase this tendency, yet much of it may be 
fairly attributed to imperfect ventilation and indigestion, 
caused by the sedentary habits of the pupils. 
Our boards of education, and all who have charge of 
our public and private schools, need to be especially watch- 
ful against all these sources of injury to the delicate 
tissues of the eye. 
We cannot too earnestly admonish all against any sort 
of reliance upon the various nostrums that are placarded 
at street corners and announced through the columns of 
the newspapers. In every case of eye disease, the patient 
should seek the counsel of a competent physician-—a pro- 
fessional oculist if one is within reach. This advice, if 
followed, will save time and money, and perhaps the eye. 
Avoid itinerant opticians, who peddle Scotch-pebble 
glasses, and who have no knowledge of the eye and no- 
understanding of its needs. It requires as much profes- 
sional skill to rightly adjust glassesto the eye as to remove 
a cataract. Badly adjusted, glasses are positively harmful, 
while well-adjusted, they are helpful to imperfect vision, 
and contribute greatly to the patient’s comfort and capac- 
ity for business. 
In speaking, a little while ago, of the treatment of 
certain forms of strabismus, I alluded to the atropine treat- 
ment, and in bringing these remarks to a close, I can not 
forbear saying more of this, the most impprtant remedy 
in the armamentarium of the oculist, without the knowl- 
edge of which we would be like a ship at sea without a 
compass. 
In the form of a solution of the neutral sulphate of atropia 9 
of the strength of from a grain to 4 grains to an ounee of 
distilled water, it is applicable in almost every affection of 
the eyeball, those alone in which there is a preternatural 
dilatation of the pupil being excepted. This remedy 
should be known and appreciated by every physician, for 
by its use we are enabled to paralyze for a time both the 
sphincter of the pupil and the ciliary muscle, thus placing 
the eye in a state of absolute repose. 
The science of ophthalmology is still in its infancy. 
It has been said, indeed, that professional oculists were 
known amongst the Greeks and Romans, and that even 
the Egyptians were familiar with the leading principles 
of ophthalmology. How much of this is simply conject- 
ural, if not truly fanciful, I shall not take time to discuss. 
Certain it is, that if the ancients possessed half the knowl- 
edge accredited to them, then ophthalmology deserves to 
rank amongst the lost arts of antiquity; for it is matter of 
history that during the 16th and 17th centuries and 
earlier half of the 18th century, the art was mainly in the 
hands of Quacks and Sciolists. 
So general'was the lack of information, that even the 
illustrious Boerhaave gravely affirmed that mercury would 
dissolve a cataract. To borrow his own Latin phraseology, 
Mercurius saepe perfectas cataradas solvit. Joseph Barth, a na- 
tive of Malta, and afterwards a professor at Vienna, was 
the earliest scientific oculist of modern times. He was to 
ophthalmology what Lavoisier was to chemistry. 
He popularized it and prepared the way for the advent 
of the von Grsefes and Arlts, whose greater discoveries 
and achievements have been such signal blessings to the 
world. 
At an early period of the present century a well-or- 
ganized Eye Infirmary was established in London, which 
has done a great deal to disseminate light through all 
parts of the UAited Kingdom. 
It is almost superfluous to say, however, that Germany 
has outstripped every other nation in this interesting 
field of investigation. 
Much of this scientific advancement is due to the in- 
vention of the ophthalmoscope, which, as improved by 10 
Loring, not only enables us to search the innermost re- 
cesses—the very adytum—of the chamber of the eyes and 
to know its condition as perfectly as the outer eye, but also 
to measure the degrees of refraction, so as to supplement 
the eye by artificial helps. 
What we need now for continued progress is a 
wholesome public sentiment which will appreciate true 
science and discountenance mercenary pretenders, whose 
treatment is as absurd as the conjurations of an Indian 
doctor or the prescriptions of a clairvoyant, but unfortu- 
nately not half so harmless. 
It is a matter of sincere congratulation that so much 
has and may be done to alleviate suffering, and even heal 
deeply-seated diseases of the eye. We look, however, to 
yet nobler triumphs of professional skill in this depart- 
ment of science. 
True the age of miracles is past, and we may not, 
therefore, hope to rival the Great Physician who could 
say to the blind, Bartimeus receive thy sight, and straight- 
way it was done; or who, on another occasion, said to the 
nameless sufferer, who had been born blind, go wash in 
the pool of Siloam, and he went and washed, and came 
seeing. 
We may, however, do much to soften the lot of that 
numerous class, who having eyes, see not or see dimly, 
and this labor, though inadequately remunerated, will 
make us like Him whose life-work was the doing of good, 
and thus, may we too, best fulfil the grander destinies of 
life, and discharge in some measure the debt we owe to 
our profession and to our common humanity.