SQUINTING, or STRABISMUS, is a well-known and common deformity, which may be defined as a want of parallelism in the visual axes, when the patient endeavors to direct both eyes to an object at the same time. The squint is said to be convergent when the eye or eyes are directed toward the nose, and divergent when they are directed toward the temple, and is termed single or double according as only one eye or both are displaced.
i The divergent-form is comparatively rare, except in consequence of a prolonged loss of sight of one eye. The causes of this affection are various. Intestinal irritation, such as the presence of worms, will often induce it slightly in children. In other cases it may be traced to the temporary cerebral irritation produced by teething; and it is a very com mon symptom in hydrocephalus and other serious head affections. 'Among other causes are a want of equal normal visual power in both eyes. in extreme short sight; hut from extensive observation with the ophthalmoscope, Mr. Dixon, surgeon the royal ophthalmic hospital, Moorfields, has come to the conclusion, that - in the great major ity of instances of confirmed squint existing in children, the optic nerves themselves are ill-developed, being usually smaller than natural, of a more or less oval form, and of a dusky color."—Holmes's .5'ysteni of Surgery, vol. ii. p. 890. If the squint is only tempo
rary, and possibly arises from intestinal irritation, the bowels must be well cleared out, and tonics subSequently given. If it• is due to some peculiarity in the visual focus of the eyes, it may be removed by the judicious use of glasses. "In every case," says Mr. Dixon, "a careful ophthalmoscopic examination is the first duty of the surgeon; and he should also take every possible care to ascertain that ne organic disease exists in the brain or orbital nerves; and that there is no tumor in the orbit, mechanically burdening the movements of the eye." The surgical operation for the cure of squint consists in the division of the muscle which, by permanently drawing the eye inward or outward, and overpowering its antagonistic muscle, induces the deformity. It is better to dispense with the use of chloroform in this operation if the patient have sufficient nerve to bear the operation without flinching, as in that case the doubt that sometimes arises as to whether the muscle has been sufficiently divided can be at once solved by directing the patient to attempt inversion of the eye; but in the great majority of cases chloroform is found necessary.