Possible Clues:

• Bit stuck in lift that hasn't open­ed, one giving the illusion of movement?
• Victor Vasarely, notably
• Painter of illusions
• 'Two for me. None for you' candy
• One employing trompe l'oeil effects
• Illusionary designer
• Creator of eye-bending designs
• Creator of some illusions
• Painter who'll make you look twice