Afterwards he studied medicine at the University of Berlin, attending the lectures of Karl Ernst Theodor Schweigger (1830-1905) and graduating in 1893.
While at Leipzig he worked under physiologist Ewald Hering (1834-1918), and with Franz Bruno Hofmann (1869-1926), he conducted studies of fusion and cyclodeviation in superior oblique muscle paresis.
During World War I, Bielschowsky established a hospital ward and Braille instruction for treatment of blinded soldiers.
In 1916, along with Carl Strehl (1886-1971), he founded the Verein blinder Akademiker Deutschlands (Association of Blinded Academics of Germany).
For his war-time contributions, he was awarded the Iron Cross for War Aid from Paul von Hindenburg and honored with the title of Geheimer Medizinalrat (Privy Medical Counselor) by Wilhelm II, German Emperor.