DEFECTS, BLEMISHES AND ABNORMALITIES OF THE HORSE’S EYE.
Some of these may be present in the absence of actual disease, and yet prove so objectionable that they disqualify the animal for any use, in which style or æsthetic appearance is demanded. Among such sources of disqualification may be noted:
1st. The small eye. One or both eyes may appear small because of internal pain and retraction within their sockets, or from actual atrophy or contraction of the eyeball, the result of deep seated disease, or the organ may be congenitally small, and deep seated in the orbit, and the thick tardy eyelids may have a narrow opening through which they can only be partially seen. This last condition usually implies a dull lymphatic constitution, low breeding and a lack of intelligence, docility and vigor.
2d. The semi-closed eye with thick, coarse, sluggish lids. In this case the bulb may be not unduly small, yet as it is not freely exposed it conveys the same general expression to the observer. Like the small eye it indicates low breeding, lack of intelligence or docility and often stubbornness or even vice.
3d. The convex eye. In this the transparent cornea describes the arc of an unduly small circle, suggesting a conical form and projecting unduly beyond the margins of the lids. It implies imperfect vision, myopia, and, it is alleged, low breeding and lack of alertness.
4th. The sunken eye. This has been already referred to under the small eye. The eyelids are usually flaccid, the upper being drawn in by its levator so as to form an angle, and the edges of the orbit are somewhat prominent. It is seen in old, worn out animals, which have lost the pads of fat in the depth of the orbit, and more commonly in animals that have suffered several attacks of recurrent ophthalmia.
5th. The projecting eye. In this case the lids are unduly contracted and the eye protrudes between them so as to show a large amount of sclerotic around the transparent cornea. This may be due to nervous strain and suffering but, however produced it is decidedly unsightly and objectionable.
6th. The weeping eye. This is always a condition of disease. It may be due to irritant gases, or solid particles, to inturned cilia, everted lids, conjunctivitis or a variety of other conditions. A careful examination may show whether it is only a transient and remediable fault of a good eye or a permanent and irremediable defect.
7th. The blear eye. With swelling and scabbing of the edges of the lids and Meibomian glands, and congestion of the adjacent conjunctiva, there is usually some blurring of the surface of the transparent cornea. The trouble is mostly chronic and constitutes a serious objection.
8th. The watch eye. In this, as in the albino, there is a lack of pigment, so that the iris and sclerotic are white or bluish white in part or in whole. Such an eye may be good and durable, but not beautiful nor attractive.
9th. Blindness of one or both eyes. In all such cases the pupil remains fixed and immovable, showing no accommodation to light and darkness, and there is a lack of prompt responsiveness on the part of the eye to sounds and objects. In amaurosis, glaucoma and cataract especially, the pupil remains widely open, and alert movements of the ears are employed to make up for the lack of sight. The condition often comes from internal ophthalmia, such as the recurrent form, and is associated with atrophy of the bulb.
10th. Eyes of unequal size. This usually implies serious disease in one, not infrequently recurring ophthalmia.
11th. Too flat corneal surface. In this case there is a manifest lack of the normal projection, the anterior surface of the cornea describing the arc of a larger circle, the visual rays coming from a distance alone converge on the retina and presbyopia occurs. In this as in myopia and other visual imperfections a horse is liable to stumble and, if nervous, to shy.
12th. Ovoid Cornea. In such cases the front of the transparent cornea has an ovoid outline the arc formed by it in one direction being that of a greater circle, than the arc which crosses this at right angles. In consequence of this, the rays impinging on the outer portions of these respective arcs do not converge to the same point on the retina and a blurred and imperfect image results. This astigmatism causes the subject to stumble and, if nervous, to shy.