Getting consumers to notice a better4you brand in a supermarket filled with thousands of products  is big business.   A few major CPG companies are combining three-dimensional computer simulations of product designs and store layout.  Vastly improved technology in the past few years has helped them actually track retinas to get a true fix on where people are looking, for how long and how often. That information has helped dispel myths about what really matters in design.  Their goal was to find which designs got noticed in the first 10 seconds a shopper looked at a shelf—a crucial window when products are recognized and placed in the shopping cart.