1) Dystrophia retinae dysacusis syndrome: Two different recessively inherited forms have been observed among 133 cases diagnosed in Finland--a country with a population of 4.6 million. 2) X-chromosomal retinoschisis: A series of 179 ophthalmoscopically verified familial cases is reported. The loci for Xg and retinoschisis are within measurable distance on the X-chromosome, but deutan dyschromatopsia is far from these. 3) Grouped pigments of the retina: No evidence of heredity was detected among 23 cases on the basis of the last four to six generations. The sex ratio is 15:8.