The state of simple visual defect without any cerebral disturbance, which usually is not present in the medical clinic, was produced in animals. This paper describes how to produce the blind animals by treatment and how to bring up the blind animals. Two experiments were made. In pilot experiment, we made two groups of complete blindness. The first group of animals were operated on both eyes in early suckling period of 14th day after birth, which was called a congenital blindness group, and the second group was operated in early childhood about twenty seven days after birth, which was called an acquired blindness group. Each blindness group consisted of four mice (dd N type), five rats (Wister type) and two dogs (mongrel). The precise experiment was a furthar study on the results of the pilot experiment, using nine rats of congenital blindness group. Three methods were used to produce complete blindness: 1. burning both eyes by a heated iron stick, 2. extirpation of both eyes with a pair of excision scissors, 3. covering of both eyes by aluminum foil with a medical bond; Aron alpha A (SANKYO, α-cyanoacrylate monomer). Artficial feeding was started at eleventh day after birth by giving 1.0ml of commercially obtained cow's milk to seventeen rats in equal amount by mean of a tuberculine syrine twice a day, in addition to mother's milk at liberty. This was mas made to prepare the animals for artificial feeding much earlier. At 15th day kneaded food, which was prepared by mixing cow's milk and weaning stuff in equal ratio in weight, was started in addition to artificial milk feeding and water at liberty. On 16th day four rats were made blind by burning method and five rats by covering method. Eight rats were controls. After operation animals were separated from motheres. The amount of kneaded food was increased according to the increment of body weight in two groups of animals. At 22nd day only solid weaning stuff was given. At 28th day usual rat-food was given. The growth of animal was watched by weighing each animal every day. It was found as the results of these treatments that blinded animals, especially, alminum leaf covered animals, out grew the normal controls.
