The Authors report on 10 subjects of the same family affected by a malformation of the ocular region, which may be classified in the group of the ptoses with blepharophimosis. These symptoms, always present, were variably accompanied by other malformations (dislocatio lateroversa canthi medialis, duplicity of the lower lacrimal points, « elongatio » of the lower canaliculi, limitation of the superior recti, synophrys, hypoplasia of the iris, of the caruncle, of the plica semilunaris and of the tarsus). The existence of a hereditary congenital malformation, which may be called «ptosis with blepharophimosis », is confirmed. In the cases reported this is probably transmitted by a dominance trait.

A family beloging to an isolated locality of Latium and comprising 362 subjects was studied. Among these subjects 63 cases of variably complicated iris atrophy, which the Authors distinguish in three degrees according to the severity of the disease, were found and studied. From the nosological point of view, glaucoma and hydrophthalmus proved to occur as secondary manifestations of the iris atrophy in this family. From the genetic standpoint it was confirmed that the transmission of the disease occurs by a dominance trait and that it probably corresponds only to a couple of autosomic allelomorphs. The penetrance seems to be almost complete, while the expressivity may be very variable.

The Authors report on dizygotic twins of 7 months and of different sex. Both twins were affected by iris atrophy, which in the male was associated with buphthalmos acquired at about 6 months of age.

The hypothesis is made that the primitive heredity consists in the iris malformation and that in this case the buphthalmos is secondary to it.

In MZ-twin-sisters, aged 19 and underdeveloped from the psychophysical viewpoint, the Authors have indentified the presence of a Verhoeff's hypertropia due to occlusion, concordant and congenitally associated with squint and nystagmus. The latter is present in the mother and in a single born sister too, who is affected also by heterophoria. This is the first report on hypertropia due to occlusion in twins.

The observation of twin-brothers of 4 years affected by congenital squint caused by ophthalmoplegia of Musculi recti externi, probably nuclear in origin, is described. This is the second report on concordant ophthalmoplegia in MZ twins.

The case of twin-sisters, 24 years old, showing congenital squint, that was corrected by surgery, hypermetropia and astigmatism is presented. The ophthalmoscopic examination revealed in one eye of both sisters, and specular-like, tortuosity of the retinal vessels, which in a subject is accompanied by twisted arteries in the vitreous body; in the other twin-sister an epipapillary membrane was observed, which is present in analogous form also in a single born brother. Furthermore, dystrophic lesions of the retina were present specular-like in both sisters. It is the first time that such a malformative syndrome is observed in concordant MZ twins.

The Authors have studied 87 pairs of MZ-twins, determining for each individual the values of both Fusional Convergence (FC) and Simultaneous Macular Perception (SMP) by means of the major amblyoscope. They have found a high degree of discordance in the FC, corresponding to 80,5 per cent, while the SMP showed a lower degree of discordance (17,2 per cent.). The Authors have observed that the highest values of FC mostly belong to the “leader twin”; they make the hypothesis that the unusual discordance of the FG in the MZ-twins depends on a higher level of will in the “leader twin”, thus representing a test of psychological discrimination between MZ-twins.