282 Mr. D. Griffin 07i an imusual Affection of the Eye, 



shall feel gratified if I can learn whether it has ever been ob- 

 served by others. 



One day in the early part of last July, after having spent a 

 considerable time in looking at various land objects through 

 a telescope, 1 perceived a very great indistinctness of vision 

 after I had left offj which I soon found existed entirely in the 

 left eye. I had kept this eye closed while I was at the tele- 

 scope ; and having often observed before that some indistinct- 

 ness of vision occurred in the same circumstances, I attri- 

 buted it to the weakness of sight that would naturally follow 

 from havhig kept that eye unemployed while using the other, 

 and did not mind it much at first. It seemed now, however, 

 so great that I covered the right eye to examine the state of 

 the other more particularly. 



I then found, with some surprise, that it gave more than 

 one image, and on directing it towards a box on the chimney- 

 piece, about eight or nine feet from me, on the front of which 

 were some large and extremely well printed letters, I per- 

 ceived that there were three distinct images of those letters 

 placed vertically one above the other. The lowest, which I 

 shall call the true image, was undisturbed from its proper 

 place. The dislocation of the second im.age was just so great 

 as to make it overlap more than the upper half of the last- 

 mentioned, and its light was scarcely, if at all, inferior to that 

 of the true one. The light of the third was much more faint 

 than that of either of the others, and its displacement was such 

 as to allow it still slightly to overlap the true image at its 

 upper edge, where the combination of the three images pro- 

 duced a dark line along the letters exactly similar in appear- 

 ance to overlying shadows. There was not the least displace- 

 ment towards either side, unless I changed my head from an 

 erect position ; and 1 could not find any trace of a fourth 

 image by the closest examination. This affection lessened 

 gradually in the course of the evening, the false images slowly 

 descending to their true place, and next day that eye was as 

 perfect as the other. 



I was for some time puzzled to account for this strange ap- 

 pearance. It seemed difficult to suppose that any functional 

 derangement of the retina could give origin to three images 

 so distinct and separate ; and though a double image is some- 

 times an attendant upon amaurotic affections of the eye, yet 

 this, so temporary in its nature, could hardly be classed with 

 such complaints. The cleanness and good definition of the 

 images seemed to indicate some optical change ; and besides 

 this, the distortion occurring all in one plane evidently pointed 

 to some single cause, and that probably a mechanical one, as 

 the origin of the whole pha^nomenon. 



