SHADY CHARACTERS: Three hot London designers are making it in the shade. Marios Schwab, due to show his collection in London today, is expected to unveil models from a new sunglass collaboration with Mykita. The Berlin-based firm previewed samples of the new line at the Silmo eyewear show in Paris over the weekend, including small stainless steel shades inspired by ones popular among clubbers in the Eighties. Meanwhile, word has it Erdem and Giles have each collaborated on spring eyewear lines with Cutler & Gross. Giles Deacon, who will present his catwalk show in Paris this season, has been a customer of Cutler & Gross for years and wears glasses, sunglasses and swimming goggles by the brand.