S6 Mr. Ware's Observations on the near 



the same person has had a near, and the other a distant 

 sight. 



It has been said by Dr. Porterfield,* that the pupils of 

 near sighted persons are more dilated than those of others. 

 This, 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 more 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 circum- 

 stance, yet in the greater number even of those cases where 

 the dilatation and contraction of the pupil are powerfully in- 

 fluenced by a difference in the strength of the light, the dis- 

 tance 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 pro- 

 bable; 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 with her needle, is always dilated very 

 nearly to the rim of the cornea ; but whenever she looks at 

 a small object, nine inches from the eye, it contracts, within 

 less than a minute, to a size nearly as small as the head of a 

 pin. Her left pupil is not affected like the right ; but in every 

 degree of light and distance, it is contracted rather more than 

 is usual in other persons. The vision is not precisely alike in 

 the two eyes ; the right eye being in a small degree near 



• Treatise on the Eye and the Manner of Vision, Vol. II. p. 38. 



