NUAR AND DISTANT SIGHT. 
215 
Although near-sightedness is, in general, gradual in its pro- Near-siphted- 
II r , • ness iu tliil- 
gress, instances occasionally occur of its existence, m a con- 
siderable degree, even in children j in whom it is sometimes 
discovered almost as soon as they begin to lake notice of the 
abjects around them. This may be occasioned by some de- 
gree of opacity in the transparent parts of the eye } but such 
a cause of near-sightedness is easily discovered by an exami- 
nation, and is quite different from that state of the eye to which 
the term myopia, or near-sightedness, is usually applied ; by 
which is simply meant too great a convexity either in the 
cornea or in the crystalline, in proportion to the distance of 
these parts from the retina. In such cases of extreme near- 
sightedness in children, it is sometimes necessary to deviate 
from a rule which, in slighter cases, I always follow’, of dis- 
couraging the use of spectacles j since, w ithout their assistance, 
lit would be impossible for them to prosecute their learning 
iwith ease or convenience. 
Extreme near-sightedness is sometimes occasioned by an Case of dis- 
ivident change in the spherical hgure of the cornea, and jig ‘■*‘'^‘'prodticing 
lassumption of a conical shape. 1 his morbid state of the cor- 
nea is not only productive of near-sightedness, but when the 
jarojection is considerable, vision is so much confused, that it 
iift'ords little or no service, and cannot be amended by any 
[glass. The cornea, in most of these cases, is pretcrnatnrally 
hin, and not unfrequently it is accompanied with symptoms of 
[general debility, under which last circumstance chalybeate 
nmedicines, and bracing applications to the eye, have been found 
: o afford considerable benefit. 
Near-sightedness, to an alarming degtee, has sometimes instance of 
nttacked young persons suddenly. A remarkable case of thie 
J o r 1 s aLinriinz near- 
kcind came under my notice a few years ago, iu a young gen- siibicdut;*. 
K have had au opportunity of conversing, have had Iheriqtit eye more 
r icar si"lited titan the left ; and I think it not improbahle, that tiiis 
i liffcmiee been the two eyes has bi en oecasioiietl by 'the liabit of n-iing 
■ i siiiale concave hand-glass ; w Inch, being most eoinniorily applii d to 
I he light eye, contributes, agreeably to the remark above-im ntioiied, 
l>o render this eye more ucar-sighted ilian the other. 
tleniaa 
