CKNTU11Y 1\. 171 



the greater light disperseth them. For the same 

 cause they need contracting ; but being contracted, 

 are more strong than the visual spirits of ordinary 

 eyes are ; as when we see through a level, the sight 

 is the stronger; and so is it when you gather the 

 eye-lids somewhat close : and it is commonly seen 

 in those that are pore-blind, that they do much 

 gather the eye-lids together. But old men, when 

 they would see to read, put the paper somewhat 

 afar off: the cause is, for that old men s spirits 

 visual, contrary to those of pore-blind men, unite 

 not, but when the object is at some good distance 

 from their eyes. 



871. Men see better, when their eyes are over- 

 against the sun or a candle, if they put their hand a 

 little before their eyes. The reason is, for that the 

 glaring of the sun or the candle doth weaken the 

 eye ; whereas the light cir cum fused is enough for 

 the perception. For we see that an over-light 

 maketh the eyes dazzle ; insomuch as perpetual 

 looking against the sun would cause blindness. 

 Again, if men come out of a great light into a dark 

 room ; and contrariwise, if they come out of a dark 

 room into a light room, they seem to have a mist 

 before their eyes, and see worse than they shall 

 do after they have stayed a little while, either 

 in the light or in the dark. The cause is, for that 

 the spirits visual are, upon a sudden change, dis 

 turbed and put out of order ; and till they be 

 recollected, do not perform their function well. For 

 when they are much dilated by light, they cannot 



