‘My work is about space and the light that inhabits it. It is about how you confront that space and plumb it with vision. It is about your seeing, like the wordless thought that comes from looking into fire.‘ 
Best known for his work ‘Roden Crater’, an ongoing installation in a volcano crater in Arizona, Turrell also developed many smaller light installations. Nevertheless, he is interested in embedding his artworks in an architectural environment, as for example with his sky-spaces. He grew up as a quaker, and sometimes it is suggested, that his fascination of the perception of light goes back to this religious beliefs.
‘First, I am not dealing with an object. The object is perception itself. Secondly, I am not dealing with an image, because I want to avoid associative symbolic thought. Thirdly, I am not dealing with a purpose or any particular focal point, either. With no object, no image and no purpose, what are you seeing? You are seeing yourself seeing.’ 
More detailed information on Turrell and the developments of his work can be found in the article from Stefan Beyst ‘James Turrell: A sculptor of life’ .