Chap. 54.] 
THE THEORY OF SIGHT. 
51 
very great distance, while there are others, again, who can only 
distinguish objects when brought quite close to them. The 
vision of many stands in need of the rays of the sun ; such 
persons cannot see on a cloudy day, nor yet after the sun has 
set. Others, again, have bad sight in the day-time, but a 
sight superior to that of others by night. Of persons having 
double pupils, or the evil eje^ we have already spoken at 
sufficient length. Blue^^ eyes are the best for seeing in the 
dark. 
It is said that Tiberius Caesar, like no other human being, 
was so endowed by J^^ature, that on awaking in the night he 
could for a few moments distinguish objects just as well as 
in the clearest daylight, but that by degrees he would find 
his sight again enveloped in darkness. The late Emperor 
Augustus had azure eyes like those of some horses, the white 
being larger than with other men ; he used to be very angry 
if a person stared intently at them for this peculiarity. Claudius 
Caesar had at the corners of the eyes a white fleshy substance, 
covered with veins, which would occasionally become suffused 
mth blood; with the Emperor Caius^ they had a fixed, steady 
gaze, while Nero could see nothing distinctly without wiak- 
ing, and having it brought close to his ejes. The Emperor 
Caius had twenty pairs of gladiators in his training-school, 
and of all these there were only two who did not wink the 
ej^es when a menacing gesture was made close to them : hence 
it was that these men were invincible. So difficult a matter is 
it for a man to keep his eyes from winking : indeed, to wink is 
so natural to many, that they cannot desist from it ; such per- 
sons we generally look upon as the most timid. 
'No persons have the eye all of one colour ; that of the 
middle of the eye is alwaj^s different from the white which 
surrounds it. In all animals there is no ipart in the whole 
body that is a stronger exponent of the feelings, and in man 
more especially, for it is from the expression of the eye that 
we detect clemency, moderation, compassion, hatred, love, 
sadness, and joy. From the eyes, too, the various characters 
of persons are judged of, according as they are ferocious, me- 
93 B. vii. c. 2. 9* Caesii." 
The same has been said also of Cardan, the elder Scaliger, Theodore 
Beza, the French physician Mairan, and the republican Camille Desmoulins,. 
Caligula. 
E 2. 
