NEAR AND DISTANT SIGHT. 
214 ^ 
After this, I inquired at several of the colleges in Oxford and 
Cambridge ; and, though there is a great diversity in the 
number of students who make use of glasses in the various 
colleges, they are used by a considerable proportion of the 
but at the nni- whole number in both Universities; and, in one college in 
versities many. ^ ^ t , ^ ^ ■ , ,• 
Oxford, I have a list of the names of not less than thirty-two out 
of one hundred and tw’enty-seven, who wore either a hand-glass 
or spectacles, between the years 1803 and 1807- It is not impro- 
bable, that some of these w'ere induced to do it solely because 
the practice was fashionable ; but, I believe, the number of such 
is inconsiderable, when compared with that of those whose 
sight received some small assistance from them, though this 
assistance could have been dispensed with, without inconve- 
nience, if the practice had not been introduced. The misfor- 
tune resulting from the use of concave glasses is this, that the 
near-sightedness is not only fixed by it, but a habit of inquiry 
is induced with regard to the extreme perfection of vision j 
and, in consequence of this, frequent changes are made for 
Explanation glasses that are more and more concave, until at length the near 
^'lasses ^ sightedness becomes so considerable, as to be rendered seri- 
creases the ously inconvenient and afflicting. It should be remembered, 
evil. I /. - 1 , 
that, for common purposes, every near-sighted eye can see 
with nearly equal accuracy through two glasses, one of which 
is one number deeper than the other ; and though the sight 
be in a slight degree more assisted by the deepest of these 
than by the other, yet on its being first used, the deepest 
number always occasions an uneasy sensation, as if the eye 
was strained. If, there’ore, the glass that is most concave be 
at first employed, the eye, in a little time, will be accommo- 
dated to it, and then a glass one number deeper may be used 
with similar advantage to the sight; and if the w’ish for enjoy- 
ing the most perfect vision be indulged, this glass may soon 
be changed for one that is a number still deeper, and so in 
succession, until, at length, it will be difficult to obtain a glass 
sufficiently concave to afford the assistance that the eye re- 
quires*. 
* I have observed, tbatmostof the near-sighted persons with whom 
Although 
