3. _Tenonitis_ very rarely occurs, but may lead to matting down of all the extra-ocular muscles and defective movements of the globe. Panophthalmitis has been known to follow this condition. =Remote.= 1. _Failure to correct the muscular error._ If the error be large it must be rectified by tenotomy of the corresponding muscle of the other eye or by the advancement of the opposing muscle of the same eye. This should not be undertaken until five or six weeks have elapsed since the previous operation. 2. _Over-correction of the muscular error at the time of the operation_ may be remedied by stitching the tenotomized muscle forward to the extent required to bring the eye straight. Advancement of the tenotomized muscle should be performed if the over-correction be only discovered after the operation. In cases with binocular vision lesser degrees of deviation may be corrected with prisms if they are causing symptoms, while small errors of over-correction, of about 3° prism, often disappear after the first few weeks. 3. _Defective movement in the tenotomized muscle_ is usually present for the first week or two after the operation, but recovery usually takes place after the muscle has regained its attachment to the globe; it may persist, however, to a slight extent; this is most liable to occur after free division of the tendon and its expansion (more especially in the case of the external rectus), or because the tendon has not been divided close enough to the globe. In patients with previous binocular vision diplopia is present after the operation on turning the eyes towards the same side as the tenotomized muscle, but this usually disappears. 4. _A granulation_ may form at the site of the tenotomy wound. It may be due to a tag hanging from the wound or to a portion of a stitch that has been imperfectly removed. It should be snipped off with scissors and the conjunctiva drawn together over its base. 5. _Proptosis_ may result from too free a division of a tendon. 6. _Retraction of the caruncle_ is best avoided by closing the conjunctival wound with a stitch, and thus pulling the caruncle forward. ADVANCEMENT Advancement is an operation undertaken to rectify a squint by forming a fresh attachment for one of the ocular muscles nearer the cornea, and at the same time shortening it. There are three main types of operation performed:-- 1. The capsulo-muscular, in which the tendon, together with the attachment of the capsule of Tenon to it, is advanced. 2. The tendon only is isolated, shortened, and advanced. 3. The tendon is shortened by folding it upon itself. The first operation is by far the most satisfactory of these, owing to the fact that a broader new insertion of the muscle is obtained, which is less likely to yield subsequently; it is the operation usually performed in this country.