Close suffers from prosopagnosia, also known as face blindness, in which he is unable to recognize faces. By painting portraits, he is better able to recognize and remember faces. On the subject, Close has said, "I was not conscious of making a decision to paint portraits because I have difficulty recognizing faces. That occurred to me twenty years after the fact when I looked at why I was still painting portraits, why that still had urgency for me. I began to realize that it has sustained me for so long because I have difficulty in recognizing faces."