Optical illusion IQ tests are challenging puzzles designed to test how well your brain can focus, analyze, and identify patterns within a very short time frame. Not only fun but also an excellent exercise for sharpening cognitive skills and enhancing attention to detail. Optical illusion IQ tests are challenging puzzles designed to test how well your brain can focus, analyze, and identify patterns within a very short time frame. Not only fun but also an excellent exercise for sharpening cognitive skills and enhancing attention to detail. Health and Fitness, Health Tips, Exercises & Workout Tips, Diet & Wellness | Times of India Lifestyle