,£80 
NEAR AND DISTANT SIGHT. 
V. 
Observations relative to the near and distant Sight of different 
Persons. By James Ware, Esq. F. R. S. From the Philo~ 
sophical Transactions for 1813. 
{Concluded from p. 216.) 
Ttn’simpcrfec- seldom alike in the two eyes, 
tion issekloni and a few cases have come under my observation, in 
alike in botli , i j j .. 
eves. which one eye of the same person has had a near, and the 
other a distant sight. 
Whether the been said by Dr. Porterfield*, that the pupils of iiear- 
piinil 111 near- sighted persons are more dilated than those of others. This, 
sighted eyes be ^ ‘ . 
diluted. ' however, does not accord with the observations I have made in 
such cases. 
It has also been commonly believed, that the size of the 
pupil is influenced by the distance of the object to which the 
attention is directed, this aperture being enlarged when the 
object is far off, and becoming more and ihore contracted as it 
is brought near. But though the activity of the fibres of the 
iris is sometimes sufficient to be visibly influenced by this cir- 
cumstance, yet, in the greater number even of thpse cases 
where the dilatation and contraction of the pupil are power- 
l»,.f,babiy not ; influenced by a difference in the strength of the light, the 
nutqiiery? distance of the object considered alone produces so little effect 
upon it as to be scarcely perceived. That it has, however, in 
general, some degree of power on the pupil is highly probable ; 
and an extraordinary instance of this kind exists, at the present 
time, in a lady between thirty and forty years of age, the pupil 
of whose right eye, when she is not engaged in reading or in 
working wiih her needle, is always dilated very nearly to the 
.. rim of the cornea : but whenever she looks at a small object, 
traction of the nine inches from the eye, it contracts, within less than a mi- 
' *'*r oi^cc'ts nute, to a size nearly as small as the head of a pin. Her left 
• coiiteiu- 
» Treatise on the eye and tlie manner of vision, vol. 2, p. 38. 
pupil 
