Born 1954 in Miyagi prefecture, Japan. Iizawa is a Japanese photography critic, historian of photography, and magazine editor.
He studied photography in Nihon University, graduating in 1977. He obtained his doctorate at University of Tsukuba in 1984. With his trilogy, "Geijutsu shashin to sono jidai (Art Photography and its Time)", "Shashin ni kaere (Go back to the photography)" and "Toshi no shisen (Glance of the City)" published in 1986, 1988 and 1989, he stood out and became the representive photography researcher of the early 20th century. Iizawa founded magazine "Deja-vu" in 1990 and was its editor in chief until 1994. He has been taking part as a judge in public competitions "Shashin-shinseiki (New Generation Photography)" and "Hitotsubo-ten (3.3m² Exhibition)", since their beginning, and through these competitions made the "girly photo" trend in the 1990s.

Reknowned as Nobuyuki Araki researcher. In 1996, he was awarded the Suntory Arts Award for his book "Shashin bijutsukan e yokoso (Welcome to the Photography Museum)". Also, he is an enthusiast for mushrooms and published books such as "Sekai no kinoko kitte (World's Mushroom Stamps)" and "Aruku kinoko (Walking Mushrooms)".
He was a part-time instructor at the Tokyo College of Photography in 1981, teaching Photography Artist Research. In 2004 and 2008, he was a part-time lecturer at Faculty of Liberal Arts, University of Tokyo, teaching history of photography in Japan.