DISEASES OF THE SKIN AND EYE. 83 



to fifteen days. The attacks may follow each other at intervals of 

 a month, more or less, but they show no particular relation to any 

 particular phase of the moon. From five to seven attacks usually 

 result in blindness, and then the other eye is liable to be attacked until 

 it also is ruined. 



Treaiment. — Is largely the same as that for simple ophthalmia. 

 During recovery a course of tonics is often very beneficial and acts 

 in assisting to ward off another attack. Such a tonic is the follow- 

 ing: Sulphate iron 1 ounce, gentian 1^ ounces, nux vomica 1^ ounces. 

 Make into twelve powders and give one powder, in feed, twice a day. 



If opacity of the cornea remains, benefit may be obtained from 

 the use of silver nitrate, 4 grains to 1 ounc^ of water, a few drops 

 dropped into the eye twice daily. A saturated solution of iodide 

 of potassium may be used in the same manner. 



CATARACT. 



Cataract is usually the result of repeated attacks of recurrent 

 ophthalmia. It is an opacity, not of the cornea, but of the crystalline 

 lens. No treatment will restore it to its normal condition. 



