Optical retailer National Vision focuses on Wal-Mart, but keeps an eye out for other business opportunities, too. The company sells low-cost prescription glasses, contact lenses, and sunglasses at more than 700 locations in 40-plus states, about 200 of which are in Wal-Mart stores in the US and Mexico under the Vision Center banner. National Vision also maintains facilities in Fred Meyer stores (Vista Optical) and on military bases (Optical Center), as well as free-standing retail locations (America's Best Contacts & Eyeglasses and Eyeglass World). The company sells contact lenses online through bestcontacts.com. National Vision is owned by investment firm Berkshire Partners.