T20 PROCEEDING <)K Tl I K ANATOMICAL AND AN Til ROl'Ol.OlilCAL 



The recorded observations from which the statistics were deduced 

 were made during the years from 1S<<> to 1 !)<):>. 



The examinations were conducted under the following condi- 

 tions: The person undergoing examination with regard to aciiteness of 

 vision, refraction and si/e of pupil, stood looking at Snellen's test types 

 at a distance of <> metres from them. The test-types were illumined 

 by two electric lamps of 10 c.p. each, one at the top, the other at I lie 

 foot of the types. Both lamps were distant H feet from the typos 

 and were shaded from the eyes of the person examined. The room 

 was also lit by four electric lamps, each of Hi c.p., suspended S feet 

 above the level of the floor. One of the lamps was 3 feet in front 

 of the person examined and 11 feet to the right; a second lamp 

 was :5 feet in front and 22 feet to the right ; a third was 13 feet in 

 front and 11 feet to the right, and a fourth was 13 feet in front 

 and 22 feet to the right. In addition to these four there' was an 

 electric lamp used for illuminating the Holmgrens wools and for writ- 

 ing purposes, close on the right of the person examined. This lamp 

 was shaded so that its direct light did not affect in any way the fundus 

 of the eye examined. All were examined under these conditions, 

 which must necessarily be stated, as it has been found ' that a person 

 can distinguish an object better in a room which is full of light than 

 when the room is dark and only the object illuminated. 



ACUTENESS OK VlSloN. 



This was determined by means of Snellen's test-types in the 

 manner above alluded to. 



Amongst the 400 students there was no case of absence of eye. 

 Of the 800 eyes there were none with no perception of light. The 

 number of eyes with normal vision (able to read D = 6 of Snellen's 

 types at a distance of (5 metres, or to distinguish an object subtending 

 a visual angle of five minutes) before the adjustment of suitable cor- 



i E. H. Shein, Bonn ; Trans. Heidelberg Ophthal. Society, in Ophthalmic 

 Review, 1901. 



