ARTIFICIAL EYE.
These are largely in use in the human being, and have been employed in the lower animals in different cases, especially in the horse, with excellent effect. The advantages may be summed up in this, that they do away with the unsightly appearance of an empty orbit with the edges of the lids turned into the dark aperture, enhance the value by restoring the face to nearly the natural appearance, and prevent the lodgment of dust and insects in the cavity.
The artificial eye may be made to appear more natural if made of glass, yet when made of horn or still better of hard rubber, colored like the normal iris and pupil, it has the advantage of greater lightness. It must be perfectly smooth so as to cause no discomfort, and should never be introduced so long as there is any irritation in the stump or conjunctiva. It may be slipped in like a button, first beneath the deeper upper lid, and then beneath the lower, and should be worn only while at work and so long as it causes no irritation nor purulent discharge. On the return of the animal to the stable, the artificial eye is taken out, washed and placed in clean pure water. The orbit should be sponged out with a weak collyrium (boric acid 1 ∶ 100).
In man, excentration is sometimes substituted for enucleation, the cornea is removed together with the lens, vitreous, choroid and retina, leaving only the sclera which contracts into a dense scar tissue with the muscles attached. Or an artificial vitreous of glass or unoxidizable metal is introduced around which the sclera is allowed to heal. This introduces an additional element of danger over the formation of a simple sclerotic stump, but, when successful, it affords a better support to the artificial eye, turning it freely in harmony with its fellow and giving it a more natural aspect.