Central sensory and motor fusion of images, once established, is usually maintained throughout life. Under certain circumstances, this ability may be lost. This gives rise to the syndrome known as horror fusionis, or acquired disruption of central fusion. We report the development of central fusion disruption in three patients with uniocular mature senile cataract. We postulate that this is the result of prolonged sensory deprivation in the cataractous eye. The loss of fusion results in a particularly troublesome type of intractable diplopia, characterized by the inability to either fuse or suppress images. To the best of the authors' knowledge, this is the first report of central fusion disruption following cataract surgery for senile cataract.