Complex sentence: He temporarily lost his vision for a few weeks after the atomic bombing of Nagasaki in 1945, and overcame great odds in the following 11 years to gain an education and achieve academic success.
Split into simpler sentences: He temporarily lost his vision for a few weeks after the atomic bombing of Nagasaki in 1945. His education was interruped by the devastation in the early postwar years, and he overcame great odds in the following 11 years to earn an education and achieve academic success.