OPTICAL INSTRUMENTS. 



167 



Goggles for Squinting. (Fig. 

 655.) These goggles are instru- 

 ments used for curing squinting, or 

 that distortion of the eyes which oc- 

 casions this disorder ; they are short 

 conical cups of ivory, horn, or hard 

 wood stained black. Through the 

 centre of each of these cups is a 

 small circular hole, about the size 

 of the pupil of the eye, for the 

 transmission of the rays of light. 

 They are mounted in a leather 

 frame, and worn continually in the 

 day time, till the muscles are 

 brought to act regularly and uni- 

 formly, so as to direct the pupil 

 straight forwards ; and by these 

 means the cure will be sooner or 

 later effected. Price, 88 cts. 



Fig. 656 is an 

 improved mount- 

 ing for the above, 

 in wire frames, 

 preventing the 

 heating of the 

 eye by the leath- 

 er mounting. 



Price, $1.50. 



