In _malignant tumours_ enucleation should only be performed when there are no signs of extra-ocular extension. If extra-ocular extension be present, evisceration of the orbit should be performed, provided there be no evidence of general metastasis. In cases of glioma of the retina it is especially desirable that the optic nerve should be cut as far back as possible and the cross-section carefully examined for gliomatous tissue, since the disease spreads to the brain along this structure. _In injuries followed by non-suppurative cyclitis_ enucleation or Frost’s operation is preferable to Mules’s operation, since cases have been recorded of sympathetic ophthalmia following the latter operation, and it is these cases of non-suppurative cyclitis which are especially prone to give rise to that disease. _Blind painful eyes_, especially when affected with glaucoma, are best removed, as occasionally the underlying cause, when not known, may prove to be an intra-ocular growth. =Instruments.= Speculum, fixation forceps (two pairs), straight scissors, strabismus hook, strong curved scissors. =Operation.= Before the anæsthetic is administered the forehead should be marked over the eye to be enucleated, so as to guard against the accident of removing the wrong eye. It is usual, at any rate in the case of hospital patients, to get their written consent for the operation. _First step._ The speculum is inserted. In the case of the right eye the conjunctiva is seized with the fixation forceps downwards and outwards, or in the case of the left eye, downwards and inwards. The straight scissors being held with the right thumb and ring finger, the conjunctiva is divided freely all the way round, as close as possible to the cornea, and dissected back. _Second step._ The capsule of Tenon is opened below the external rectus by grasping it with forceps and buttonholing it with the scissors. The strabismus hook is passed through the opening made in Tenon’s capsule with its concavity against the globe, turned upwards beneath the tendon, and the latter is pulled well forward and freely divided from above downwards between the hook and the globe. The superior and inferior recti are treated in a similar manner. In dividing the internal rectus a small portion should be left attached to the globe, so that subsequently it can be grasped with forceps to rotate the globe outwards when dividing the optic nerve. _Third step._ The globe is dislocated between the lids by opening the speculum widely and pressing it backwards. If the globe will not dislocate, it is either because the tendons are imperfectly divided, or the palpebral aperture is too small to allow of its delivery; the latter is liable to be the case in small children or in those with a staphylomatous globe. In such cases the palpebral fissure should be enlarged by dividing the outer canthus. [Illustration: FIG. 134. ENUCLEATION. Method of suturing the conjunctiva; the suture requires no knot.]