In some ways, Prada’s butterfly-shaped sunglasses are here to stay. Having celebrated its 100-year anniversary, it’s safe to say that the company founded by brothers Mario and Martino Prada has stood the test of time. The PR 20U is an example of this. Its elegant 50s style in two-color acetate is an elaborate design: ivory on the front and cherry on the inside that take classic retro-style traits from the past, it looks so elegant while maintaining the style of the firm. Violet Gradient lenses.