THE EYEBALL AND EYELIDS. 3l5 



XIX. 

 MOTIONS OF THE EYEBALL AND EYELIDS. 



We shall consider the muscles of the eye, first, 

 as necessary to its preservation ; secondly, as ne- 

 cessary to it as the organ of sense. We do not 

 reflect on those actions of our frame which are 

 most admirable in themselves, which minister 

 continually to our necessities, and perfect the ex- 

 ercise of our organs, until we are deprived of 

 them : like unnatural children, unconscious or un- 

 mindful of indulgence, we feel only the loss of 

 benefits. " With much compassion," says the re- 

 ligious philosopher, " as well as astonishment at 

 the goodness of our loving Creator, have I con- 

 sidered the sad state of a certain gentleman who, 

 as to the rest, was in pretty good health, but only 

 wanted the use of those two little muscles that 

 serve to lift up the eyelids, and so had almost lost 

 the use of his sight, being forced, as long as this 

 defect lasted, to shove up his eyelids with his 

 own hands." 1 have often thought of this saying 

 when I have seen a patient in all respects in 

 health, but without the power of raising the eye- 

 lids. 



There is a motion of the eyeball, which, from 

 its rapidity, has escaped observation. In the in- 



