DISEASES OF THE EYE. 95 



Diseases of the eye, more or less severe, seem to be common, or at any rate not 

 uncommon, among the seals, ranging in virulence from a mere supf>uration of the 

 eyelids to complete blindness. Cases of suppurating eyelids or lachrymal glands may 

 be seen among the pups at almost any time, on almost any rookery, but many of the 

 pups are totally blind from some disease of the retina, the cornea being transparent, 

 but the pupil greatly dilated, giving to the eye a peculiar greenish appearance, as in 

 seals recently killed. One young male was seen on Polovina which seemed to be 

 suffering from cataract in the left eye, the cornea being transparent, but the pupil 

 showing as a white spot, as though the lens were opaque. Most of the cases of 

 blindness among the bulls are, however, the direct outcome of rookery battle, and 

 one-eyed bulls are by no means rare, nor do they seem as much handicapped by the 

 loss as one might expect, since a one-eyed bull on Zapadni gave more trouble than 

 auy six of his fellows with the normal complement of eyes. There are frequent 

 instances among the pups of blindness in one eye, seemingly from accident, the 

 cornea being sometimes thick and white, sometimes ulcerated or even perforated. 

 Similar disease of the eye is produced in man by the irritation of foreign particles, 

 such as iron filings, sand, etc., and there is no reason why it should not be similarly 

 brought about among seals, although it is often the direct result of a bite. There is 

 more or less sand on all rookeries, and particularly on the hauling grounds and 

 localities where the pups i)od out, and it would be strange indeed if the seals never 

 got any in their eyes. 



The eye of a pup killed on Zapadni in August, showing a fine case of perforation 

 of the cornea, was preserved. This has been carefully examined by Dr. D. K. Shute, 

 who has made a special study of diseases of the eye, and he has made the following 

 rei)ort : 



The whole cornea is densely opaque, the corneal layers being replaced by fibrous tissue 

 (leucoma). About the center of the cornea there is distinct evidence that a perforation had taken 

 place. A well-marked band of cicatricial tissue is shown along the site of the perforated cornea. 

 The cicatrix contains pigment from the iris. The iris is inliltrated with inflammatory celLs (leuco- 

 cytes) and its pupillarj' margin is adherent to the cicatrix and the cornea (synechia anterior). 



The uveal jjigment has been detached at various xioiuts of the iris and lies in the vitreous. 



The ciliary body was detached and dragged toward the site of the corneal perforation and ia 

 infiltrated Avith numerous inflammatory cells (cyclitis). 



There is a large amount of inflammatory material in the idace of the lens and adjacent vitreous 

 composed of fibers and leucocytes. 



The retina was detached and swollen, and the choroid was infiltrated with large numbers of 

 inflammatory cells. 



The perforation through the cornea is about 4 millimeters in diameter. 



I am of the opinion that the probable cause of the diseased eye was the presence of foreign bodies 

 in it, which could easily be brought about by windstorms and the consequent blowing of sand against 

 the cornea. 



Dr. ISTorgaard has called my attention to the fact that there is also a widespread 

 disease among domesticated animals, known as infectious opthalmia,' which presents 

 symptoms precisely similar to those noticed among the pups, so that it is by no means 

 improbable that a like disease may account for many of the sore eyes seen. It is of 



' "Keratitis acuta infectiosa, Moller, Lchrbuch der Augenheilkunde fur Thierarzte, p. 25; "Infec- 

 tious ophthalmia," W. F. Weese, American Veterinary Review, Jan., 1897, pp. 707-711. 



