Popular Science, joulukuu 1935
Q. - Why is it that babies' and animals' eyes which are blue at birth frequently change to another color? - O. T E., Cambridge, Mass.
A. - Newborn babies or animals, with the exception of hose which have very black eyes, have no pigment in the front of the iris. The apparent lue color of their eyes is propably due to the suspension of exceedingly fine particles in the front of the iris. These particles absorb certain rays of light which, in combination, we recognize as blue. The pigment of the iris, while present at birth, does not become fully distributed until some time later.