exposure will be undertaken when ages of the children are more firmly established. 3. Ophthalmological findings. Ophthalmological examinations in- cluding slitelamp studies sat yearly intervals have not revealed any opacities of the lens that might be associated with irradiation effects. No differences in visual acuity between exposed and unexposed people have been noted. The 3 and 4 year examinations revealed an increase in incidence of pterygium in the exposed population. Arcus senilis and senile cataracts are of slightly higher incidence in the exposed group but have not show an ine crease since exposure, In general moat of the Marshallese people examined have superior vision and accommodation compared to our standards. The ine cidence of glaucoma, myopia, retinal arteriosclerosis, and squint are iow. Many of the people have large corneas which will be further studied. 4. Fertility. It has not been possible to show even a temporary sterility on the basis of comparison of frequency of pregnancies in the exposed with the unexposed people. There have been 18 healthy babies born in each of the exposed and unexposed groups since the accident. The preg- nancies were distributed fairly evenly over the 4 year period. 5. In utero effects and effects on pregnancy. irradiated in-utero, the third trimesters. babies. Four fetuses were One was in the first, two in the second, and one in Pull term deliveries resulted in apparently normal There were 5 miscarriages or babies born dead or dying shortly after birth. Lack of vital statistics in this regard makes it impossible to evaluate these findings with certainty. ~9= However, from comparison with