What you see is not a direct recording of reality. The human brain constantly interprets light, depth, and context, filling gaps with assumptions to make sense of the world. Optical illusions like the Müller-Lyer and Jastrow effects reveal how identical shapes can appear different simply because surrounding cues change. Why it matters: perception is an inference engine, not a camera, and understanding its limits is critical for design, safety systems, and human-machine interfaces. Follow for dai