J. LeConte on Binocular Vision. 177 
the ideal of ocular motion, though an ideal seldom or never re- 
alized in nature; or does the rotation of the eye subserve some 
Conclusions. 
_ The most important conclusions arrived at in this paper 
_ May be briefly summed up as follows. 
1. The axial and focal adjustments of the eye are not so in- 
_ Separably associated as is generally supposed ; but on the con- 
when distinctness of vision requires it they may be com- 
pletely dissociated.* 
., 2. In this dissociation, the contraction of the pupil associates 
itself with the focal in preference to the axial adjustment. 
3. In optic convergence there is a rotation of both eyes on 
optic axes outward ; and this rotation increases with the de- 
gree of convergence. : 
4 In inclining the visual plane downward the rotation of 
eyes for the same degree of convergence , unt 
When the visual plane is inclined 45° downward the rotation 
omes zero for all degrees of convergence. Below the incli- 
hation of 45° the rotation is inward. In turning the eyes 
hia except in cases of strong convergence, the rotation 
decreases slightly but does not reach zero ;} im strong con- 
vergence it increases as stated by Meissner. 
. 5. Besides the rotation produced by optic convergence there 
18 also a decided inclination of the vertical line of demarkation 
Upon the horizontal line of demarkation, frag ve -bae re 
‘Ae degree of convergence. This change in the relation or these 
two lines is probably tie result of distortion of the ocular globe. 
* While these pages were passing through the press, I discovered that in this fs 
Conclusion nee Donders aid others’ “All ious experi- 
, mes however, were a By men of glasses. Mine were "made with the 
t See this statement modified in note on p. 165. 
— 
“9 ee 
age 
