\.-2(\ PROrKKDINGS OF TIIK ANATOMICAL AND ANTHROPOLOGICAL 



of the right eye only was measured, and the measurement was made 

 by comparing the size of the pupil with that of the discs of a pnpilo- 

 meter on the back of an ophthalmoscope. These discs could be 

 rotated in succession until one of equal size to that of the pupil was 

 adjacent to it, and this disc gave the diameter in millimetres. The 

 conditions of light were as previously stated, and that has an im- 

 portant bearing on the average size, as different averages given by 

 different observers are in a great measure due to the conditions of 

 light. Coppez, 1 in measuring the size of pupil, seated the person 

 examined facing a clear window but out of the sunlight. Under 

 these conditions he found the physiological diameter of the pupil 

 varied from 2 to 4 mm., the greater number being between 2| and 

 3 mm. Woinow - found the size of pupil to vary between 2 - 44 and 

 5 - 82 mm. M. Lans, 3 after allowing accommodation to rest by 

 keeping the person examined fifteen minutes in a dark room, took 

 an instantaneous photograph of the pupil by magnesium light, before 

 the pupil had time to react. He obtained an average diameter of 

 7 to 8 mm. 



Among the 400 students the average size of the pupil among the 

 males was 6'4 mm., and among the females 5'9 mm. Thus the 

 average size of the pupil was larger among the males than among 

 the females by '5 mm. Tanger, however, states that females have 

 larger pupils than men. 



In reference to the size of the pupil in the different forms of 

 refraction it has been stated that hypermetropic eyes are apt to have 

 small pupils, owing to the constant effort of accommodation, while 

 in myopia the pupils are said to be wide. Among the students the 

 average size of the pupil in hypermetropic eyes was (37 mm., in 

 myopic eyes 6 '3, in mixed astigmatic eyes 6 '9. In these groups the 

 refraction in anisometropic individuals was taken as that of the eye 

 the pupil of which was measured. This result gives a larger average 



1 Revue Generale d' Ophthalmoloijic, 1903. 



- Ophthalmometrie, Vienna, 1871. 



3 Revue Generate d'Ophtlialmoloyic, 1899. 



