CASE 46.--Miss A--, æt. 17, suffered from diplopia for a few weeks, a year and a half ago; for the last half year the diplopia is continuous, and striking squint is stated to be sometimes present. Myopia 2 D. on both sides, visual acuteness = 5/9. On fixation of an object about 4 m. distant, the left eye deviates inwards at most 2 mm.; homonymous double images, with a red glass and on correction of the myopia, which were united by means of prism 14° at a distance of 5 m., without red glass (with retinal images alike on both sides) prism 8° sufficed to unite them. If a vertically deviating prism is held before one eye, the double images stand just above one another when looking at an object 20 cm. off, on nearer approach they are crossed. On May 3rd, 1879, tenotomy of the left internal rectus with small conjunctival wound without loosening of the conjunctiva, and union of the conjunctival wound by a suture. On May 8th, single vision, also with correction of the myopia and with red glass. Facultative divergence = 2°. On May 14th, with correction of the myopia, there was still single vision for distance; however, with red glass double images occurred again; and at the end of May the condition of the double images was just the same as before the operation. On vertical shifting of one visual field by a weak prism the double images are brought into a vertical line by means of prism 16°, with the base outwards. Therefore, on July 1st, the right internal rectus was also divided, with small conjunctival wound without loosening of the conjunctiva and without suture. The evening after the operation slight divergence on covering. On July 24th, binocular single vision is present; with red glass homonymous double images at 5 m., corrected by prism 4°. This time the result was final; for in the middle of October, three months after the operation, the report was exactly like the one of July 24th above stated. CASE 47.--Mrs. A--, æt. 33, has suffered for six months from alternating convergent squint with diplopia, for a short time even a parallel position is still possible. On the right myopia 4 D., V. = 6/12. On the left myopia 4 D., V. 6/9. Single vision occurs to 22 cm., at a greater distance homonymous double images, whose mutual distance remains the same when looking to one side. On correction of the myopia a prism of at least 32° is necessary for the union of the double images for an object at 4 m. Two days after tenotomy of the internal recti on both sides, the facultative divergence amounted to 7° (at 4 m.) on correction of the myopia. Single vision was also present when looking strongly to one side, and with differentiation of one retinal image by a red glass.