To prove that you have 20/20 vision, you need to find the odd couch out of the lot but in under 15 seconds, and enhance your cognitive abilities and memory function via these brain teasers and optical illusions. To prove that you have 20/20 vision, you need to find the odd couch out of the lot but in under 15 seconds, and enhance your cognitive abilities and memory function via these brain teasers and optical illusions. Health and Fitness, Health Tips, Exercises & Workout Tips, Diet & Wellness | Times of India Lifestyle