But Cupid is not guided by colour alone in his choice. However beautiful
the colour of an eye, it loses half its charm if it lacks lustre. A
bright, sparkling eye is the most infallible index of youthful vigour
and health, whereas the lack-lustre eyes of ill-health can never serve
as windows from which Cupid shoots his arrows. No wonder that the poets
have searched all nature for analogies to the lustre of a maiden’s eye,
comparing it to sun and stars, to diamonds, crystalline lakes, the light
of glow-worms, glistening dewdrops, etc.
What is the source of this light which shines from the eye and
intoxicates the lover’s senses? Several answers to this question have
been suggested. Twenty-five hundred years ago Empedokles taught that
“there is in the eye a fine network which holds back the watery
substance swimming about in it, but the fiery particles penetrate
through it like the rays of light through a lantern” (Ueberweg). And a
notion similar to this, that there is a kind of magnetic or nervous
emanation which beams from the eye and is a direct efflux of the soul,
was entertained in recent times by Lavater and Carus. It was apparently
supported by the peculiar light which may be seen occasionally in the
eyes of cats, dogs, and horses in the twilight; but this has been proved
to be a purely physical phenomenon of reflection, due to an anatomical
peculiarity in the eyes of these animals.
Some writers have attempted to account for the lustrous fire of the eye
by attributing it to the increased tension of the eyeball brought about
through certain joyous and exciting emotions. Dr. Hugo Magnus, however,
denies that these emotions ever increase the tension of the eyeball: “We
know from numerous exceedingly minute measurements that there is no such
thing whatever as a rapid change of tension in the eye, as long as it is
in a healthy condition.” In some diseases, especially in cataract or
glaucoma, such an increased tension does occur, indeed, but it does not
in the least impart to the eye the sparkle of joyous excitement. Hence
Professor Magnus concludes that “the mimic significance of the eye
cannot be conditioned by changes in the form of the eyeball, through
tension or pressure on it.”
His own theory (as developed in his two interesting pamphlets, _Die
Sprache der Augen_ and _Das Auge in seinen aesthetischen und
culturgeschichtlichen Beziehungen_) is that the greater or less
brilliancy of the eyes depends entirely on the movements of the eyelids.
Instead of calling the eye the window of the soul, it is more correct to
say that the cornea is a mirror which, like any other mirror, reflects
the light that falls on it. The higher the eyelids are raised the larger
becomes the mirror, and the more light is therefore reflected. Now it is
well known that exciting emotions like joy, enthusiasm, anger, and pride
have a tendency to raise the eyelids, while the sad and depressing
emotions cause them to sink and partially cover the eyeball; hence joy
makes the eyes sparkling, while grief renders them dull and lustreless.
The old poetic and popular notion that the lustre of the eye is a direct
emanation of the human soul must therefore be abandoned. The sparkling
eye is a mere physical consequence of the involuntary raising of the
eyelids brought about through exhilarating or exciting emotions.
This theory of Dr. Magnus doubtless comes nearer the truth than the
others referred to; and the fact that snakes’ eyes, though small, are
proverbially glistening, apparently because they are lidless, may be
used as an additional argument in his favour, which he overlooked. Yet
his view does not cover the whole ground; for it does not explain why,
after weeping, or when we are weary or ill, we may open our eyes as
widely as we please without making them appear lustrous.
This difficulty suggested to me the theory that, though partly dependent
on the movements of the eyelids, the lustre of the eyes is due
originally to the tension and moisture of the _conjunctiva_.
The _conjunctiva_, though consisting of 6-8 layers of cells, is an
extremely thin and highly sensitive, transparent membrane, which lines
the surface of the eyeball as well as the inside of the eyelids. In this
membrane is located the pain which we feel if dust, etc., flies into our
eyes. In order to wash out any particles that may get into the eye, and
to prevent the lid from sticking to the eyeball, the lachrymal glands
constantly secrete the water, which, during an emotional shower,
consolidates into tear-drops.
Now, just as “the rose is sweetest washed with morning dew,” so the eye
is brightest and most fascinating which glistens in an ever fresh supply
of lachrymal fluid. After weeping, this supply is temporarily exhausted,
hence not only are the eyes “sticky” and the lids difficult to raise,
but even if they are raised there is no lustre; you look in vain for
“Cupid’s bonfires burning in the eye.” But when we wake up from
refreshing sleep in the morning, or when we take a walk in the bracing
country air, the eye sparkles its best and “emulates the diamond,”
because at such a time all the vital energies, including of course those
of the lachrymal glands, are incited to fresh activity, which they lose
again after prolonged use of the eye, thus making it appear duller in
the evening.
Thus we can readily account for those lights in the eye “that do mislead
the morn.” Yet it is probable that (although in a less degree than dewy
moisture) the tension and translucency of the conjunctiva are also
concerned in the production of a liquid, lustrous expression. Though the
eyeball itself may not undergo any changes in tension, the conjunctiva
doubtless does. The eyeball rests on a bed of fatty tissue which shrinks
after death, owing to the emptying of the blood-vessels and the
consolidation of the fat, which makes a corpse appear “hollow-eyed.” The
same effect, to a slighter degree, is caused by disease and excessive
fatigue, making the eyes sink into their sockets. This sinking must
diminish the tension of the conjunctiva, both under the eyelids and on
the surface of the eyeball; and in shrinking it becomes less transparent
and glistening.
The following observations of Professor Kollmann indirectly support my
theory that the conjunctiva is the source of the eye’s lustre: “After
death this transparent membrane (the conjunctiva) becomes turbid, the
eye loses its lustre and becomes veiled. The surface reflects but a
faint degree of light, the eye is ‘broken.’” The loss of lustre extends
to the white of the eye, but is less noticeable, perhaps because there
lustre does not blend with colour, as in the iris region.
Fashionable young ladies who dance throughout the night several times a
week may well be disgusted with the _blue_ rings which appear around
their sunken eyes. These rings are a warning that they need “beauty
sleep” and fresh air to fill up the sockets again with healthy fat and
_red_ blood, so as to increase the tension of the conjunctiva and
stimulate the flow of dewy moisture on which the lustre of the eye
depends. There are tears of Beauty as well as of anguish and joy.