received sight by the formation of an artificial pupil. 531 
knew the direction from whence the light emanated. With 
regard therefore to the degree of sight, this lady was more 
completely blind than the boy in the celebrated case related 
by Mr. Cheselden, in the 35th volume of the Transactions 
of the Royal Society ; for in that instance the boy knew 
black, white, and scarlet apart from one another ; and when 
in a good light he had that degree of sight, which generally 
continues in an eye affected with cataract ; whereas in this 
lady, the pupil being completely shut up, no light could reach 
the retina, except such rays as could pass through the sub- 
stance of the iris. 
When she was placed under my care she had reached her 
46th year. The right eye-ball was collapsed, but the left 
retained its natural globular form. The cornea of this eye 
was transparent, except at one point near its circumference, 
where there was a linear opacity, which had probably been 
the cicatrix of the wound made during the operation in her 
infancy. The anterior chamber of the eye was of its natural 
capacity, but I could not distinguish any vestige of a pupil, 
some streaks of yellow lymph being deposited in an irregular 
manner over the central part of the iris. There was every 
reason to believe that the retina was sound ; for though she 
could not perceive objects, nor had any notion of colours, yet 
the circumstance already mentioned of her being able to dis- 
tinguish between a very light and a very dark chamber, and 
between a gloomy day and sunshine, rendered it probable 
that the nerve was in a sound and natural state. Under this 
impression, I thought that the restoration of her sight by 
making an artificial pupil was practicable, and certainly well 
worthy of a trial. Accordingly, on the 26th of January, I 
