Sender: cdiablo Chengfeng Gaoshan Pojian, message area: ASCIIart Title: Optical illusions Müller illusion and Ebbinghaus illusion Sending station: BBS Shuimu Tsinghua Station Tue Oct 26 22:50:32 2004, within the station This is relatively common. I can’t explain it. The circle in the middle below and the two horizontal lines look different.