340 Observations relative to 
my eye has varied from what it was a few years ago, when 
I was able to distinguish both near and distant objects cor- 
rectly, through No. 8. This is ground to a radius of eight 
inches on one side, and six inches on the other, and with 
it I can still read a type like that in which the Transactions 
of the Royal Society are printed; but am unable to distin- 
guish through it many distant ‘objects , which | formerly’ 
used to see distinctly —Hence it appears that my eyes have 
a confined range of distinct vision, extending oniy to an’ 
inch, or ap ich and a quarter; and that they remain nearly 
in the same state in which they were many years ago with 
regard to near objects, but have lost a part of the power 
which they formerly possessed, of adjusting themselves to 
distant oncs. In this Jast respect, they differ from the eyes 
of those who have naturally a distant sight, since, as sucli 
persons advance in life, they usually feta the power of 
distinguishing distant objects, but lose that of seeing those 
that are near. It appears to militate also against the com- 
mon observation, that as near-sighted persons grow older 
they become less near-sighted ;- since my eyes, on the eon- 
trary, are more near- -sighted, * the age of fifty-five, than 
they were at twenty- five, dd lam now obliged to employ 
deeper concaye glasses than I then used to see distant ob- 
jects, though I am: not able to see distinctly through them 
things that are near. 
The alteration which ‘has taken place in my range of vi- 
sion, I have reason to believe is not unusual. Dr. Wells, 
in his paper on this subdject, mentions the case of a gentle- 
man, who, like me, was near-sighted, and whose sight, as 
he advanced in life, had undergone a similar change. —The 
following is also an instance of this kind, that is still more 
remarkable. Mr. L. sixty-six years of age, who has spent 
a great part of his lite in the West Indies, and whose sight, 
when he was young, enabled him to see both near “aie 
distant objects with great preci sion, began, at the age of 
forty, to experience a difficulty in reading and writing. He 
immediately procured convex spectacles of the first number 
sold by opticians, which glasses are usually ground to a 
focus of forty-six or forty- -eivht inches, and by the aid of 
these he continued to read aud write with ease (distinguish 
ing perfectly in the usual way all distant objects withont 
them,) until he was fifty. At this time he first began to 
perceive an indistinetness in the appearance of things at a 
distance ; and, on trying with different glasses, he diss 
covered that, by looking through a double concave glass of 
the sixth number, (which is > ground to a radius of eight 
inches 
