The sun. [volume] (New York [N.Y.]) 1833-1916, 1879-02-23
ETIsSIGHT and READING.
How the IpJu,iou. Eneci. Upsn tue Eye. Jay
he a volded.

NJ. Javel, IN n recent lecture. tries to an
swcr tho question. Why is reading specially
fatgulng eXcrciso2 ana also suggests some
remedies for this fatigue. First. VI. Jaycl says
reading requires an absolutely permanent mp
uiivaiton oi the eycsight. resulting IN a pcrma-
nent tension Of the organ, which mas be- meas
ured b. the amount OF fatigue or 10y he pro-
duction 0f permanent myopy. secondly, books
are printed in black on white ground. The
contrast which can be imagined. The third
pt 'ullgrty lies i'm the arrangement OF the char
actcrs IN horizontal lines. over which run our
eyes.
II we maintain during readinga perfect i'm.
mobility OF the book and the head the printed
lines are applied successtVc!y g. the same rars
~ the retin1. while the intors PAGES. more
bright. also uflsct certain regions 90 the retina
always tho same There must result from this
u fatigue ana Qgous 90 that which w experience
when we make experiments ~ accidental in-
ages, " md physicists will admit that there IS
nothing more disastrous for the sight than the
prolonged conten citation OF these limoges.
Lastly, and most IL portaut Of all, IN NJ Javels
estimation, Is the continual variation OF the
distance OF tho eye from the = int OF nNation
on the book. A simple calculation demonstrates
That the accommodation on the eye 10 the IugH
undergOes a distinct variation in proportion "a,
the eye passes from the beginning 10 the end Of
each linz. and that this variation ~ all the
gre1ter IN proportion 10 the nenrness OF the
book 10 the eye and the length OF the line.
As to the rules which NJ. Javel iucucates IN
order TINT the injurious elfccs OF reading may
be avoided with reference 81 tho permanent NJ
plicaton Of the eyes, he counsels 10 AVOID OK
cess. 20 take notes in reading, to stop in order
10 reflect. or even 90 roll cigarette; hut not 10
90 on reading Tor hours on end without stop
ping. As TO the contrast between the white Of
the paper and the black characters. various eA-
pcrlmcnts nave been made in the intrudu ton
Of cOored papers. NJ. Jnyei ulyscs the adpp.
ton Of IA slightly yellow tint. Bui the nature OF
the yellow 20 be used j. not matter Of lndiflOr-
cncc; no would desire a yellow resulting from
the absence OF the blue rays. analogous to that
Of papor made from wood paste. and VIII n IL
often mistakenly corrected hv the addition Of
IN ultramarlNc blue. which produces gray. an 4
not white. IA Javel has been led to this cunclu-
sion 10th from practical observation and 81. %
theoretically from the relation which mus. exist
between the two eyes ana the cOiors Of the apec-
trum
His third advice II 10 give preference 10 small
volumes which can bo held IN the hand. which
obylat-s tho necessity Of the book being k"pt
fixed IN one place. and ia" fatigue resulting
from accidental images. lastly. NJ. Javel No.
NlHes the avoidance OF too long lines and
therefore no prcior5 small volumes. ard for the
Same reason those journals which Hrr pr ni"d
in narrow columns. OF course every one knows
thHt il H. exceedingly INJURIOUS to read with in
euNiclcu' light. or o. read too small print. aud
other common rulc'
NJ JaNcl conclude by protesting against an
inkidluus ussc rtipn winch has recently been
made Ia u nuis Nuoring dcHutry (H"runhy.
no doubt. according to which the dec, ca uf civil
liIatiou al a poopo il prouortonai 10 tho num-
her oil tle shorls GIFTED shown io .cA il 49, sta
tistics 'he cvtrene economy OF Hight, the abuse
ot reading to the drtrimout of reelection and
the observation ~ rcal facts. the employment Of
Gothic rllurUcteTs ma OF a too broad column
for books ana journals are the conditions which,
NJ JHyol bel eyes. lead to mY0pV, especially II
successive generations have been subjected TO
these Injurious influences.