1894.] The Refractive Character of the Eyes of Horses. 419 



paralysis of accommodation is concerned, little, if any, is produced 

 even by repeated instillations of this drug. 



My results have been calculated according to the rule given by 

 Morton : For hypermetropia deduct + 1 D from the weakest convex 

 lens which causes the shadow to move with the mirror ; for myopia 

 deduct + 1 D from the strongest concave lens with which the shadow 

 continues to move with the mirror. 



The following table (p. 420) exhibits the results of the enquiry. 



The table shows that of the 100 eyes examined 



51 were myopic and astigmatic. 



2 ,, hypermetropic and astigmatic. 



6 ,, affected with mixed astigmatism. 

 39 myopia. 



1 with hypermetropia. 



1 emmetropia. 



The varieties of astigmatism which existed were as follow : 



Compound myopic astigmatism 43 



Simple 8 



Compound hypermetropic astigmatism 1 



Simple ,, 1 



Mixed astigmatism 6 



In the eyes affected with myopia and astigmatism, the horizontal 

 meridian was nearly always the meridian of least curvature. Berlin 

 and Lang and Barrett had also observed the same fact. In my table 

 of the 51 eyes there were only nine exceptions to this rule. 



The amount of error which existed in each refraction was as 

 follows : 



Myopia, 39 Eyes. 



Amount of error, 0'25 D G eyes. 



0-50,, 20 



> 1*25 ,, 5 



1-50 4 



,) 2'25 ,, 2 



>i 2'50 1 



3-00,, 1 



Only once in 39 eyes was the amount of 3 D reached, whilst the 

 most common amount of error was 0'50 D. 



VOL. LT. 2 G 



