Complex sentence: Grace Bashara Greene (1928--2004) was an American Visionary artist noted for her assemblage work and for the Visionary environment she created in her house, which was featured in the documentary film Eyeopeners.
Split into simpler sentences: Grace Bashara Greene (1928--2004) was an American Visionary artist noted for her assemblage work. She is considered a Visionary artist known, for the Visionary environment she created in her house, which was featured in the documentary film Eyeopeners.